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Sample records for acrylic acid esters

  1. 40 CFR 721.2805 - Acrylate ester.

    Science.gov (United States)

    2010-07-01

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

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

    Directory of Open Access Journals (Sweden)

    G.Torosyan

    2013-06-01

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

  3. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Science.gov (United States)

    2010-07-01

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

  4. Scanning thermal lithography of tailored tert-butyl ester protected carboxylic acid functionalized (meth)acrylate polymer platforms.

    Science.gov (United States)

    Duvigneau, Joost; Schönherr, Holger; Vancso, G Julius

    2011-10-01

    In this paper, we report on the development of tailored polymer films for high-resolution atomic force microscopy based scanning thermal lithography (SThL). In particular, full control of surface chemical and topographical structuring was sought. Thin cross-linked films comprising poly(tert-butyl methacrylate) (MA(20)) or poly(tert-butyl acrylate) (A(20)) were prepared via UV initiated free radical polymerization. Thermogravimetric analysis (TGA) and FTIR spectroscopy showed that the heat-induced thermal decomposition of MA(20) by oxidative depolymerization is initially the primary reaction followed by tert-butyl ester thermolysis. By contrast, no significant depolymerization was observed for A(20). For A(20) and MA(20) (at higher temperatures and/or longer reaction times) the thermolysis of the tert-butyl ester liberates isobutylene and yields carboxylic acid groups, which react further intramolecularly to cyclic anhydrides. The values of the apparent activation energies (E(a)) for the thermolysis were calculated to be 125 ± 13 kJ mol(-1) and 116 ± 7 kJ mol(-1) for MA(20) and A(20), respectively. Both MA(20) and A(20) films showed improved thermomechanical stability during SThL compared to non cross-linked films. Carboxylic acid functionalized lines written by SThL in A(20) films had a typically ~10 times smaller width compared to those written in MA(20) films regardless of the tip radius of the heated probe and did not show any evidence for thermochemically or thermomechanically induced modification of film topography. These observations and the E(a) of 45 ± 3 kJ mol(-1) for groove formation in MA(20) estimated from the observed volume loss are attributed to oxidative thermal depolymerization during SThL of MA(20) films, which is considered to be the dominant reaction mechanism for MA(20). The smallest line width values obtained for MA(20) and A(20) films with SThL were 83 ± 7 nm and 21 ± 2 nm, whereas the depth of the lines was below 1 nm, respectively.

  5. Two Players Make a Formidable Combination: In Situ Generated Poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) Cross-Linking Gel Polymer Electrolyte toward 5 V High-Voltage Batteries.

    Science.gov (United States)

    Ma, Yue; Ma, Jun; Chai, Jingchao; Liu, Zhihong; Ding, Guoliang; Xu, Gaojie; Liu, Haisheng; Chen, Bingbing; Zhou, Xinhong; Cui, Guanglei; Chen, Liquan

    2017-11-29

    Electrochemical performance of high-voltage lithium batteries with high energy density is limited because of the electrolyte instability and the electrode/electrolyte interfacial reactivity. Hence, a cross-linking polymer network of poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) (PAMM)-based electrolyte was introduced via in situ polymerization inspired by "shuangjian hebi", which is a statement in a traditional Chinese Kungfu story similar to the synergetic effect of 1 + 1 > 2. A poly(acrylic anhydride) and poly(methyl methacrylate)-based system is very promising as electrolyte materials for lithium-ion batteries, in which the anhydride and acrylate groups can provide high voltage resistance and fast ionic conductivity, respectively. As a result, the cross-linking PAMM-based electrolyte possesses a significant comprehensive enhancement, including electrochemical stability window exceeding 5 V vs Li+/Li, an ionic conductivity of 6.79 × 10-4 S cm-1 at room temperature, high mechanical strength (27.5 MPa), good flame resistance, and excellent interface compatibility with Li metal. It is also demonstrated that this gel polymer electrolyte suppresses the negative effect resulting from dissolution of Mn2+ ions at 25 and 55 °C. Thus, the LiNi0.5Mn1.5O4/Li and LiNi0.5Mn1.5O4/Li4Ti5O12 cells using the optimized in situ polymerized cross-linking PAMM-based gel polymer electrolyte deliver stable charging/discharging profiles and excellent rate performance at room temperature and even at 55 °C. These findings suggest that the cross-linking PAMM is an intriguing candidate for 5 V class high-voltage gel polymer electrolyte toward high-energy lithium-on batteries.

  6. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section 175.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings...

  7. Study of protein-probe interaction and protective action of surfactant sodium dodecyl sulphate in urea-denatured HSA using charge transfer fluorescence probe methyl ester of N,N-dimethylamino naphthyl acrylic acid.

    Science.gov (United States)

    Mahanta, Subrata; Singh, Rupashree Balia; Guchhait, Nikhil

    2009-03-01

    We have demonstrated that the intramolecular charge transfer (ICT) probe Methyl ester of N,N-dimethylamino naphthyl acrylic acid (MDMANA) serves as an efficient reporter of the proteinous microenvironment of Human Serum Albumin (HSA). This work reports the binding phenomenon of MDMANA with HSA and spectral modulation thereupon. The extent of binding and free energy change for complexation reaction along with efficient fluorescence resonance energy transfer from Trp-214 of HSA to MDMANA indicates strong binding between probe and protein. Fluorescence anisotropy, red edge excitation shift, acrylamide quenching and time resolved measurements corroborate the binding nature of the probe with protein and predicts that the probe molecule is located at the hydrophobic site of the protein HSA. Due to the strong binding ability of MDMANA with HSA, it is successfully utilized for the study of stabilizing action of anionic surfactant Sodium Dodecyl Sulphate to the unfolding and folding of protein with denaturant urea in concentration range 1M to 9M.

  8. SYNTHESIS OF ACRYLIC ESTERS IN PHASE TRANSFER CATALYSIS: KINETICS AND ECOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    GAGIK TOROSYAN

    2012-06-01

    Full Text Available Phase-Transfer Catalysis (PTC technology is used in the commercial manufacture and also in pollution mitigation treatment processes. In the paper is demonstrated the synthesis of esters of acrylic and metacrylic acids, which have wide applications in the industry for the synthesis of unique polymeric materials, by phase transfer catalysis method. It is necessary to notice that the synthesis of acrylic acids in PTC medium is more important because that compounds are more sensitive at acidic and basic conditions. Here is shown that the offered method has more advantages in comparison with the traditional methods. PTC is characterized by a higher degree of conversion of raw materials into useful products, smaller material and power resources consumption. The offered method for acrylic ester synthesis in comparison with the traditional methods has more advantages: higher process rates, mild reaction conditions, allowing lower energy costs, the complete elimination of hazardous and dangerous organic solvents, all leading to a sharp reduction of air pollution, and volume of generated wastewaters.

  9. Nano-emulsion based on acrylic acid ester co-polymer derivatives as an efficient pre-tanning agent for buffalo hide

    Directory of Open Access Journals (Sweden)

    Farouk Abd El-Monem

    2017-05-01

    Full Text Available Acrylic copolymer nanoemulsions were prepared based on methyl methacrylate (MMA and butyl acrylate (BA. The prepared acrylic copolymer emulsions were characterized using solid content, rheological properties, molecular weight, MFFT and TEM. The prepared polymers were used as pre-tanning of the depickled hide to enhance the physico-mechanical properties of tanned leather. The key parameters which affect exhaustion and fixation of chrome tan as well as shrinkage temperature of the tanned leather were studied and evaluated using SEM, shrinkage temperature and the mechanical properties of the pre-tanned leather. The results showed that, the prepared polymers A & C are the best polymers in improving the physical properties of the treated leather. Furthermore, the shrinkage temperature and the mechanical properties of the tanned leather were improved. In addition, a significant enhancement in the texture of the leather treated by the polymers was noticed as proved by scanning electron microscopy (SEM.

  10. Fumaric acid esters.

    Science.gov (United States)

    Rostami Yazdi, Martin; Mrowietz, Ulrich

    2008-01-01

    Several clinical studies have shown that systemic therapy with fumaric acid esters (FAEs) in patients with moderate to severe psoriasis is effective and has a good long-term safety profile. For therapeutic use, tablets with a defined mixture of FAEs (dimethylfumarate [DMF] and three different salts of monoethylfumarate) are registered in Germany. There is evidence that DMF is the most essential component in this formulation with an antipsoriatic effect. Currently, there are few data on the pharmacokinetics of fumarates in human beings. DMF seems to act as a prodrug for its main metabolite: monomethylfumarate. This hypothesis was supported by the observation that only monomethylfumarate was detected in the plasma of human beings after the oral administration of FAEs. FAEs have been tested in different biological assays, and effects such as inhibition of the nuclear factor kappa B pathway or induction of apoptosis by DMF have been described. For these data, the role of DMF as a modulator of intracellular glutathione plays an important role.

  11. Ionizing radiation-induced copolymerization of 2-ethylhexyl acrylate and acrylic acid and ionomer formation

    Science.gov (United States)

    Weaver, Alia

    The ionizing radiation-induced polymerization of acrylate esters is a technique employed for the curing of such materials for a variety of adhesive, coating, ink, and lithographic applications. The work presented in this dissertation involves the synthesis of a copolymer composed of 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AA) using pulsed electron beam and gamma irradiation. The structure and synthesis kinetics of this copolymer were investigated by 1H nuclear magnetic resonance (NMR), electron pulse radiolysis with kinetic spectroscopic detection (PR-KSD), and Fourier transform infrared spectroscopy (FTIR). The effects of total dose, dose rate, and acrylic acid content on the polymerization reaction were studied. The conversion of 2-EHA monomer into polymer at a given total dose was found to be enhanced at lower dose rates and higher concentrations of acrylic acid. The pulse radiolysis investigation of the polymerization of 2-EHA and AA was performed through studies of four different types of systems: (i) neat 2-EHA, (ii) 2-EHA/methanol (MeOH) solutions, (iii) mixtures of 2-EHA and AA, and (iv) 2-EHA/AA/MeOH solutions. The build-up of carbon-centered neutral 2-EHA free radicals in neat 2-EHA was found to obey a second order rate law with a rate coefficient of ((7 +/- 3) x 108)epsilon EHA·, whereas in 2-EHA/AA mixtures it was found to obey a pseudo-first order rate law with a rate coefficient of (1.5 +/- 0.3) x 10 10 mol-1 dm3 s-1. This phenomenon is suggested to originate in the increased H+ ion concentration in the presence of acrylic acid, which leads to a faster neutralization step of 2-EHA radical anions as they are transformed into neutral free radicals during the initiation step of the reaction. An investigation of the formation of ion-containing copolymers (known as ionomers) was performed using the radiation-synthesized poly(2-EHA-co-AA) and iron cations. Verification of successful incorporation of iron into the copolymer was identified by an

  12. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  13. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin...

  14. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in producing...

  15. FTIR study of hydrogen bonding between substituted benzyl alcohols and acrylic esters

    Directory of Open Access Journals (Sweden)

    P. Sivagurunathan

    2016-11-01

    Full Text Available Hydrogen bonding between substituted benzyl alcohols (benzyl alcohol, o-aminobenzyl alcohol, o-chlorobenzyl alcohol and o-nitrobenzyl alcohol and acrylic esters (methyl methacrylate, ethyl methacrylate is studied in carbon tetrachloride by using the FTIR spectroscopic method. Utilizing the Nash method, the formation constant (K of the 1:1 complexes is calculated. Using the K value, the Gibbs free energy change (ΔG0 is also calculated. The calculated formation constant and Gibbs free energy change values vary with the substituent of benzyl alcohol and ester chain length, which suggests that the proton donating ability of substituted benzyl alcohols is in the order: o-aminobenzyl alcohol < benzyl alcohol < o-chlorobenzyl alcohol < o-nitrobenzyl alcohol, and proton accepting ability of acrylic esters is in the order: methyl methacrylate < ethyl methacrylate.

  16. Fumaric acid esters in dermatology

    OpenAIRE

    Uwe Wollina

    2011-01-01

    Fumaric acid esters (FAE) are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF) and three salts of monoethylfumarate (MEF) have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like gra...

  17. (Diisopinocampheyl)borane-Mediated Reductive Aldol Reactions of Acrylate Esters: Enantioselective Synthesis of Anti-Aldols

    Science.gov (United States)

    Allais, Christophe; Nuhant, Philippe; Roush, William R.

    2013-01-01

    The (diisopinocampheyl)borane promoted reductive aldol reaction of acrylate esters 4 is described. Isomerization of the kinetically formed Z(O)-enolborinate 5Z to the thermodynamic E(O)-enolborinate 5E via 1,3-boratropic shifts, followed by treatment with representative achiral aldehydes, leads to anti-α-methyl-β-hydroxy esters 9 or 10 with excellent diastereo- (up to ≥20:1 dr) and enantioselectivity (up to 87% ee). Results of double asymmetric reactions of 5E with several chiral aldehydes are also presented. PMID:23885946

  18. Fumaric acid esters in dermatology

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

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

  19. Fumaric acid esters in dermatology.

    Science.gov (United States)

    Wollina, Uwe

    2011-07-01

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

  20. Synthesis, properties and applications of interacting blends of acrylated novalac epoxy resin based poly(ester-amides and vinyl ester

    Directory of Open Access Journals (Sweden)

    Pragnesh N. Dave

    2016-09-01

    Full Text Available Epoxy resin based unsaturated poly(ester-amide resins (UPEAs were prepared by the reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  1. A novel (S)-(+)-decursin derivative, (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]chromen-3-yl-ester, inhibits ovalbumin-induced lung inflammation in a mouse model of asthma.

    Science.gov (United States)

    Yang, Eun Ju; Song, Gyu-Yong; Lee, Ji-Sook; Yun, Chi-Young; Kim, In Sik

    2009-03-01

    (S)-(+)-Decursin is a coumarin compound present in herbal extracts that has various biological activities. (S)-(+)-Decursin attenuates pathophysiologic progression in cancer, bacterial infection and neuropathy. Asthma is an inflammatory disease associated with increased infiltration of leukocytes, especially eosinophils, and secretion of mucus into the airways. Although (S)-(+)-decursin, as well as (S)-(+)-decursin analogues, have various pharmacological properties, the effect of these compounds on asthma is not known. In the present study, we synthesized (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]chromen-3-yl-ester (compound 6, C6) from (S)-(+)-decursin and examined if C6 had any inhibitory effects on lung inflammation in a mouse model of ovalbumin-induced asthma. C6 significantly inhibited the leukocytosis (p allergic airway diseases.

  2. Acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.

    Science.gov (United States)

    Wang, C C; Lee, C M

    2006-01-01

    The aim of this study is to isolate the acrylic acid utilizing bacteria from the ABS resin manufactured wastewater treatment system. The bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. The aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. The results are: twenty strains were isolated from the ABS resin manufactured wastewater treatment system and twelve of them could utilize 600 mg/l acrylic acid for growth. Seven of twelve strains could tolerate the acrylonitrile and acrylamide toxicity, when the concentration was below 300 mg/l. Bacillus thuringiensis was one of the seven strains and the optimum growth temperature was 32 degrees C. Bacillus thuringiensis could utilize acrylic acid for growth, when the initial acrylic acid concentration was below 1,690.4 mg/l. Besides this, when the initial acrylic acid concentration was below 606.8 mg/l, the acrylic acid removal efficiency exceeded 96.3%. Bacillus thuringiensis could tolerate 295.7 mg/l acrylamide and 198.4 mg/l acrylonitrile toxicity but could not tolerate 297.3 mg/l epsilon-caprolactam.

  3. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new...... phase at ~0.8 GPa and remains molecular to 7.2 GPa before polymerising on decompression to ambient pressure. The resulting product is analysed via Raman, FT-IR spectroscopy and Differential Scanning Calorimetry and found to possess a different molecular structure compared with polymers produced via...

  4. Synthesis and characterization of polycaprolactone/acrylic acid ...

    Indian Academy of Sciences (India)

    ... of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery ... by measuring diffusion coefficient () and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were ...

  5. A facile one-pot synthesis of acrylated hyaluronic acid.

    Science.gov (United States)

    A, Sigen; Xu, Qian; McMichael, Peter; Gao, Yongsheng; Li, Xiaolin; Wang, Xi; Greiser, Udo; Zhou, Dezhong; Wang, Wenxin

    2018-01-25

    The synthesis of acrylated hyaluronic acid (HA-A) normally requires 2 to 3 steps of modification, needs laborious purification and also increases the risks of HA degradation. Here, we report that the conjugation of acrylate groups to hyaluronic acid can be successfully achieved via a new facile one-pot approach. Two types of new HA-A hydrogels (via chemical or UV crosslinking) were developed and applied for 3D cell encapsulation.

  6. Tetrabutylammonium Bromide Media Aza-Michael Addition of 1,2,3,6-Tetrahydrophthalimide to Symmetrical Fumaric Esters and Acrylic Esters under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Mohammadreza Zamanloo

    2010-10-01

    Full Text Available The aza-Michael addition of 1,2,3,6-tetrahydrophthalimide with symmetrical fumaric esters has been performed efficiently in a solvent-free system at 100 °C and using 1,4-diazabicyclo[2.2.2]octane (DABCO as a base in the presence of tetrabutylammonium bromide (TBAB. The products were obtained in good to high yields within 2.5-7.0 h. This reaction worked well on linear alkyl fumarates and was not effective with nonlinear alkyl fumarates. Although the reaction was also applicable to acrylates such as n-butyl acrylate, methacrylates and crotonates were not suitable Michael acceptors for this reaction.

  7. Use of fumaric acid esters in psoriasis

    OpenAIRE

    Roll Antonie; Reich Kristian; Boer Almut

    2007-01-01

    Fumaric acid esters (FAE) are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950′s. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate(DMF) and salts of monoethylfumarate(MEF) as main compounds. In 1994, Fumaderm ® an enteric-coated tablet containing DMF and calcium, magnesium, and zinc salts of MEF was approved for the treatment...

  8. Decarboxylation-based traceless linking with aroyl acrylic acids

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  9. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    NARCIS (Netherlands)

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  10. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

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

  11. Effect of acrylic acid on the properties of polyvinylpyrrolidone ...

    African Journals Online (AJOL)

    Hydrogels based on polyvinylpyrrolidone (PVP) networks grafted with acrylic acid (AAc) was prepared by using γ-rays from a Co-60 source at room temperature. The parameters like effect of radiation dose and concentration of AAc were studied. The properties such as gel content, swelling behavior and thermal stability ...

  12. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Science.gov (United States)

    2011-12-14

    ... AGENCY 40 CFR Part 180 Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption AGENCY...-propenoate and ethenylbenzene (CAS Reg. No. 25036-16-2); also known as butyl acrylate-methacrylic acid...-risk polymers are described in 40 CFR 723.250(d). Butyl acrylate-methacrylic acid-styrene polymer...

  13. 40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of an acrylic acid - acrylamide... Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a... generically as salt of an acrylic acid - acrylamide terpolymer (PMN P-99-817) is subject to reporting under...

  14. Dipentaerythritol penta-acrylate phosphate - an alternative phosphate ester monomer for bonding of methacrylates to zirconia

    Science.gov (United States)

    Chen, Ying; Tay, Franklin R.; Lu, Zhicen; Chen, Chen; Qian, Mengke; Zhang, Huaiqin; Tian, Fucong; Xie, Haifeng

    2016-12-01

    The present work examined the effects of dipentaerythritol penta-acrylate phosphate (PENTA) as an alternative phosphate ester monomer for bonding of methacrylate-based resins to yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and further investigated the potential bonding mechanism involved. Shear bond strength testing was performed to evaluate the efficacy of experimental PENTA-containing primers (5, 10, 15, 20 or 30 wt% PENTA in acetone) in improving resin-Y-TZP bond strength. Bonding without the use of a PENTA-containing served as the negative control, and a Methacryloyloxidecyl dihydrogenphosphate(MDP)-containing primer was used as the positive control. Inductively coupled plasma-mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) were used to investigate the potential existence of chemical affinity between PENTA and Y-TZP. Shear bond strengths were significant higher in the 15 and 20 wt% PENTA groups. The ICP-MS, XPS and FTIR data indicated that the P content on the Y-TZP surface increased as the concentration of PENTA increased in the experimental primers, via the formation of Zr-O-P bond. Taken together, the results attest that PENTA improves resin bonding of Y-TZP through chemical reaction with Y-TZP. Increasing the concentration of PENTA augments its binding affinity but not its bonding efficacy with zirconia.

  15. Hybrid thermosets from vinyl ester resin and acrylated epoxidized soybean oil (AESO

    Directory of Open Access Journals (Sweden)

    2011-01-01

    Full Text Available A series of hybrids composed of styrene crosslinkable vinyl ester (VE and acrylated epoxidized soybean oil (AESO were produced via free radical-induced crosslinking. The VE/AESO ratio was changed between 75/25 and 25/75 wt%. Moreover, to support phase grafting the VE/AESO = 50/50 wt% hybrid was modified with phthalic anhydride in various amounts (1, 5 and 10 wt%. The structure of the hybrid systems was investigated by dynamic mechanical thermal analysis (DMTA, differential scanning calorimetry (DSC, and atomic force microscopy (AFM. The properties of the systems were assessed by static flexural and fracture mechanical tests. The resistance to thermal degradation was inspected by thermogravimetric analysis (TGA. The results suggested that the hybrids have an interpenetrating network (IPN structure. With increasing AESO content the stiffness (modulus, strength and glass transition temperature (Tg of the hybrids decreased, whereas their ductility increased. Phthalic anhydride caused an adverse trend. Both the fracture toughness and fracture energy increased with increasing AESO content. They were less affected by adding phthalic anhydride phase couplant. Interestingly, the hybrids outperformed the parent VE and AESO in respect to resistance to thermal degradation.

  16. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  17. 40 CFR 721.10147 - Acrylate derivative of alkoxysilylalkane ester and mixed metal oxides (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate derivative of... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10147 Acrylate derivative of... reporting. (1) The chemical substance identified generically as acrylate derivative of alkoxysilylalkane...

  18. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly( -caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2008-01-01

    Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid, subsequ......Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid...... distribution (1.09). The hydroxy chain end of Br-PCL-OR was modified by reacting with a-(2,4-dinitrophenylthio)acetic acid or a-(4methoxytritylthio) acetic acid resulting in heterotelechelic PCL incorporating protected thiol and bromoester functionalities. It was then employed as macroinitiator in NiBr2(PPh3......)2 catalysed ATRP of tBA. ATRP of tBA provided diblock copolymers with low polydispersity index (1.17-1.39) while preserving the protected thiol function. Sequential or simultaneous removal of 2,4-dinitrophenyl or 4-methoxytrityl and tert-butyl ester groups resulted in HS-PCL-b-PAA. The PCL backbone remained...

  19. A (S)-(+)-decursin derivative, (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]-chromen-3-yl-ester, attenuates the development of atopic dermatitis-like lesions in NC/Nga mice.

    Science.gov (United States)

    Kim, In Sik; Kim, Dong-Hee; Yun, Chi-Young; Lee, Ji-Sook

    2013-03-01

    (S)-(+)-decursin is a biological coumarin compound isolated from Angelica gigas Nakai. (S)-(+)-decursin and its analogue have a variety of pharmacological activities. In the present study, the anti-inflammatory effect of a (S)-(+)-decursin derivative, (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano [3,2-g]-chromen-3-yl-ester (Compound 6, C6), on in vitro and in vivo atopic dermatitis was investigated. C6 suppressed the secretion of IL-6, IL-8, and monocyte chemotactic protein-1 increase by the house dust mite extract in the eosinophilic leukemia cell line and THP-1 cells. C6 inhibited the production of TARC, IL-6, and IL-8 increase by IFN-γ and TNF-α in the human keratinocyte cell line. In the in vivo experiment, NC/Nga mice were sensitized to 2,4-dinitrochlorobenzene, and then C6 or dexamethasone (Dex) were orally and dorsally administered for three weeks. C6 treatment reduced the skin severity score compared with that of the control group. C6 inhibited the thickening of the epidermis and inflammatory cell infiltration into the dermis by evaluating the histological examination. The serum immunoglobulin E (IgE) level decreased in the C6-treated group compared with that of the control group. The inhibitory effect of C6 on IgE concentration was similar to that of Dex. The levels of IL-4, IL-5, IL-13, and eotaxin increased after treatment with concanavalin A in mouse splenocytes. The cytokine levels of the C6-treated group were lower than those of the control group. Taken together, C6 may attenuate atopic dermatitis-like lesions through its anti-inflammatory effect, such as inhibition of IgE and inflammatory cytokines, and it may be valuable as a therapeutic drug for the treatment of atopic dermatitis.

  20. Biosynthetic pathway for acrylic acid from glycerol in recombinant Escherichia coli.

    Science.gov (United States)

    Tong, Wenhua; Xu, Ying; Xian, Mo; Niu, Wei; Guo, Jiantao; Liu, Huizhou; Zhao, Guang

    2016-06-01

    Acrylic acid is an important industrial feedstock. In this study, a de novo acrylate biosynthetic pathway from inexpensive carbon source glycerol was constructed in Escherichia coli. The acrylic acid was produced from glycerol via 3-hydroxypropionaldehyde, 3-hydroxypropionyl-CoA, and acrylyl-CoA. The acrylate production was improved by screening and site-directed mutagenesis of key enzyme enoyl-CoA hydratase and chromosomal integration of some exogenous genes. Finally, our recombinant strain produced 37.7 mg/L acrylic acid under shaking flask conditions. Although the acrylate production is low, our study shows feasibility of engineering an acrylate biosynthetic pathway from inexpensive carbon source. Furthermore, the reasons for limited acrylate production and further strain optimization that should be performed in the future were also discussed.

  1. Hemocompatibility of Chitosan/poly(acrylic acid) Grafted Polyurethane Tubing

    OpenAIRE

    Lee, Hyun-Su; Tomczyk, Nancy; Kandel, Judith; Composto, Russell J.; Eckmann, David M.

    2013-01-01

    The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tu...

  2. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    OpenAIRE

    Keslarek Amauri José; Leite Carlos Alberto P; Galembeck Fernando

    2004-01-01

    Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM). Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the par...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-05

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

  4. Coating materials and solvents. 2. Acrylic acid, acrylate, and MMA; Toryo yozai. 2. Akurirusan oyobi akurirusan esuteru MMA

    Energy Technology Data Exchange (ETDEWEB)

    Akazawa, Y. [Nippon Shokubai Co. Ltd., Osaka (Japan)

    1997-09-01

    This paper describes the production process, its scale, physical properties and usage of acrylic acid, acrylate for general use, and MMA (methyl methacrylate). The propylene oxidation process is only one process for the industrial production of acrylic acid and acrylate due to its economical predominance. Annual production of acrylic acid in the world has reached to about 2.2 million tons. Relatively high growth rate is forecasted also in the future. In Japan, the acrylate is used for paints, adhesive materials, and fibers. The industrial production process of MMA includes ACH (acetone cyanhydrin) process, new ACH process, isobutylene process, MAN (methacrylonitrile) process, and ethylene carbonylation process. Demand and supply of MMA are characterized especially by the high proportion of export from Japan to the Asian region. Methacrylic resins are used for various materials, such as tail lamp lenses and meter panels of automobiles, and laser disks, CD-ROM and MD pick-ups in the field of electronic industry. Consumption of these resins is steadily extended. 16 refs., 6 figs., 7 tabs.

  5. Synthesis and characterization of superabsorbent hydrogels based on hydroxyethylcellulose and acrylic acid.

    Science.gov (United States)

    Fekete, Tamás; Borsa, Judit; Takács, Erzsébet; Wojnárovits, László

    2017-06-15

    Hydroxyethylcellulose (HEC)/acrylic acid (AAc) copolymer gels with superabsorbent properties were synthesized from aqueous solutions by radiation-initiated crosslinking. The effect of the acrylic acid content on gel properties was determined at different synthesis conditions. The partial replacement of the cellulose derivative with acrylic acid improved the gelation, leading to higher gel fraction and lower water uptake even in very low concentrations (1-5%). In the presence of acrylic acid lower dose and solute concentration was required for the gel synthesis. The molecular properties of the hydroxyethylcellulose also had a major effect on the gelation: higher molecular mass resulted in better gel properties. The acrylic acid also affected the electrolyte sensitivity of the hydrogels: while pure HEC gels were unaffected by the ionic strength of the solvent, the water uptake of HEC/AAc gels decreased with the salt concentration. The sensitivity also depended on the acrylic acid ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Catalytic Cracking of Lactide and Poly(Lactic Acid) to Acrylic Acid at Low Temperatures.

    Science.gov (United States)

    Terrade, Frédéric G; van Krieken, Jan; Verkuijl, Bastiaan J V; Bouwman, Elisabeth

    2017-05-09

    Despite being a simple dehydration reaction, the industrially relevant conversion of lactic acid to acrylic acid is particularly challenging. For the first time, the catalytic cracking of lactide and poly(lactic acid) to acrylic acid under mild conditions is reported with up to 58 % yield. This transformation is catalyzed by strong acids in the presence of bromide or chloride salts and proceeds through simple SN 2 and elimination reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  7. Use of fumaric acid esters in psoriasis.

    Science.gov (United States)

    Roll, Antonie; Reich, Kristian; Boer, Almut

    2007-01-01

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

  8. Use of fumaric acid esters in psoriasis

    Directory of Open Access Journals (Sweden)

    Roll Antonie

    2007-01-01

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

  9. Alternative Production of Fatty Acid Methyl Esters from Triglycerides ...

    African Journals Online (AJOL)

    The catalysts activity was tested in thermocatalytic cracking of triglyceride; a direct conversion process for fatty acid methyl esters (biodiesel). The SZ1 not only exhibited higher conversion of triglycerides but higher fatty acid methyl esters (FAMEs) yields of approximately 59% after 3h as compared to SZ2 (32%). In addition ...

  10. Polymerisation by acrylamide and acrylic acid inverse suspension

    Directory of Open Access Journals (Sweden)

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  11. Water absorbency of chitosan grafted acrylic acid hydrogels

    Science.gov (United States)

    Astrini, N.; Anah, L.; Haryono, A.

    2017-07-01

    Acrylic acid (AA) monomer was directly grafted onto chitosan (CTS) using potassium persulfate (KPS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. One factor affecting the swelling capacity of the obtained hydrogel, KPS concentration, were studied. The hydrogel products were characterized using Fourier Transform Infrared spectroscopy (FTIR) for chemical structure and scanning electron microscopy (SEM) for morphology. Swelling of the hydrogel samples in distilled water and saline solution ( 9% NaCl ) was examined. Swelling capacity of the CTS-g-PAA hydrogels in distilled water (88.53 g/g) was higher than in NaCl solution (29.94 g/g) The highest swelling capacity value was obtained when the grafted reaction was carried out using 2.5wt% initiator

  12. Crosslinkers of Different Types in Precipitation Polymerization of Acrylic Acid

    Directory of Open Access Journals (Sweden)

    H. Eshaghi

    2013-01-01

    Full Text Available Crosslinked poly(acrylic acids were prepared using two types of crosslinker by precipitation polymerization method in a binary organic solvent. N,N’-methylenebisacrylamide (MBA and polyethylene glycol dimethacrylate (PEGDMA-330 were used as low-molecular weight and long-chain crosslinkers, respectively. The effect of various types of crosslinkers on polymer characteristics (i.e., gel content, equilibrium swelling, glass transition temperature, and rheological properties was investigated. Maximum amount of viscosity was obtained by using long-chain crosslinker. The Flory-Rehner equation and rubber elasticity theory were used to discuss the network structure of polymer. It was observed that, the glass transition temperature (Tg of the synthesized polymer containing PEGDMA-330 is higher than that of polymer containing MBA. Apparent and rotational viscosity were used to determine the optimal crosslinker type. In addition, the consistencycoefficient (m and flow behavior index (n parameter of Ostwald equation were investigated as well.

  13. Inert Reassessment Document for PEG Fatty Acid Esters

    Science.gov (United States)

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

  14. A stability study of plasma polymerized acrylic acid films

    Science.gov (United States)

    Cools, Pieter; Declercq, Heidi; De Geyter, Nathalie; Morent, Rino

    2018-02-01

    A medium pressure parallel-plate DBD set-up was used for the deposition of carboxylic acid-rich films using acrylic acid as precursor. A variety of discharge powers (21-33 W) and monomer flow rates (0.25-0.5 g/h) were applied to develop a range of coatings from highly unstable to completely stable in aqueous solutions. FT-IR and XPS were used to identify which coatings were stable under dynamic incubation conditions and what influence plasma operating parameters had on functional group preservation. White light interferometry was also used to calculate deposition rates (66-126 nm/min) and to determine the deposition regime (monomer deficient). Human foreskin fibroblasts were seeded onto the complete range of investigated samples and the effects of coating (in)stability on cell adhesion, viability and morphology were systematically studied. Results showed that the 27 W-0.25 g/h treatment conditions resulted in the most stable coatings. Although a concentration of only 0.7% of carboxylic acid groups was found under these experimental conditions, the positive effects of a highly acid-rich surface were still maintained as cell-material interactions were significantly enhanced.

  15. SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT ...

    African Journals Online (AJOL)

    The synthesis of fatty acid ethyl ester from chicken fat waste using ZnO/SiO2 heterogeneous catalyst was carried out using two-step procedures of acid pretreatment by esterification and transesterification of the pretreated oil. The first step reduces the high free fatty acid in the oil to an acceptable level for transesterification ...

  16. Selective synthesis of thiodiglycol dicarboxylic acid esters via p ...

    Indian Academy of Sciences (India)

    The esterification of thiodiglycol and long alkyl-chain carboxylic acids is reported. Reaction of thiodiglycol with carboxylic acid via -TsOH/C-catalysed direct esterification afforded thiodiglycol dicarboxylic acid esters in good yields and chemoselectivity. The use of immobilized -TsOH on activated carbon as catalyst is ...

  17. A Convenient Synthesis of Amino Acid Methyl Esters

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-05-01

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

  18. Selective synthesis of thiodiglycol dicarboxylic acid esters via p ...

    Indian Academy of Sciences (India)

    Abstract. The esterification of thiodiglycol and long alkyl-chain carboxylic acids is reported. Reaction of thiodiglycol with carboxylic acid via p-TsOH/C-catalysed direct esterification afforded thiodiglycol dicar- boxylic acid esters in good yields and chemoselectivity. The use of immobilized p-TsOH on activated carbon.

  19. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  20. Microwave-assisted preparation of naphthenic acid esters

    Directory of Open Access Journals (Sweden)

    VERA CIRIN-NOVTA

    2006-12-01

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

  1. Controlled radical fluorination of poly(meth)acrylic acids in aqueous solution.

    Science.gov (United States)

    Dong, Yucheng; Wang, Zhentao; Li, Chaozhong

    2017-08-17

    Fluorinated alkenes exhibit very poor reactivity in copolymerization with non-fluorinated polar monomers such as acrylates. Herein we describe a convenient method for the synthesis of poly(vinyl fluoride-co-acrylic acid) and poly(2-fluoropropene-co-methacrylic acid) copolymers. Thus, the silver-catalyzed decarboxylative radical fluorination of poly(acrylic acid) with Selectfluor in water at room temperature affords poly(vinyl fluoride-co-acrylic acid) copolymers in high yields with well-defined molecular weights and polydispersities. A linear correlation is observed between the extent of fluorination and the amount of Selectfluor, indicating that the copolymer of virtually any monomer ratio can be readily accessed by controlling the amount of Selectfluor. This controlled decarboxylative fluorination is extended to poly(methacrylic acid), leading to well-defined poly(2-fluoropropene-co-methacrylic acid) copolymers.Fluorinated alkenes have very poor reactivity in copolymerizations with non-fluorinated polar monomers. Here the authors show silver-catalyzed decarboxylative radical fluorination of poly(acrylic acid) with Selectfluor in water at room temperature to form poly(vinyl fluoride-co-acrylic acid) copolymers.

  2. Oral fumaric acid esters for psoriasis.

    Science.gov (United States)

    Atwan, Ausama; Ingram, John R; Abbott, Rachel; Kelson, Mark J; Pickles, Timothy; Bauer, Andrea; Piguet, Vincent

    2015-08-10

    Psoriasis is a chronic inflammatory skin condition that can markedly reduce life quality. Several systemic therapies exist for moderate to severe psoriasis, including oral fumaric acid esters (FAE). These contain dimethyl fumarate (DMF), the main active ingredient, and monoethyl fumarate. FAE are licensed for psoriasis in Germany but used off-licence in many countries. To assess the effects and safety of oral fumaric acid esters for psoriasis. We searched the following databases up to 7 May 2015: the Cochrane Skin Group Specialised Register, CENTRAL in the Cochrane Library (Issue 4, 2015), MEDLINE (from 1946), EMBASE (from 1974), and LILACS (from 1982). We searched five trials registers and checked the reference lists of included and excluded studies for further references to relevant randomised controlled trials. We handsearched six conference proceedings that were not already included in the Cochrane Skin Group Specialised Register. Randomised controlled trials (RCTs) of FAE, including DMF monotherapy, in individuals of any age and sex with a clinical diagnosis of psoriasis. Two review authors independently assessed trial quality and extracted data. Primary outcomes were improvement in Psoriasis Area and Severity Index (PASI) score and the proportion of participants discontinuing treatment due to adverse effects. We included 6 studies (2 full reports, 2 abstracts, 1 brief communication, and 1 letter), with a total of 544 participants. Risk of bias was unclear in several studies because of insufficient reporting. Five studies compared FAE with placebo, and one study compared FAE with methotrexate. All studies reported data at 12 to 16 weeks, and we identified no longer-term studies. When FAE were compared with placebo, we could not perform meta-analysis for the primary outcome of PASI score because the three studies that assessed this outcome reported the data differently, although all studies reported a significant reduction in PASI scores with FAE. Only 1 small

  3. A key step in the formation of acrylic acid from CO2 and ethylene: the transformation of a nickelalactone into a nickel-acrylate complex.

    Science.gov (United States)

    Fischer, Reinald; Langer, Jens; Malassa, Astrid; Walther, Dirk; Görls, Helmar; Vaughan, Gavin

    2006-06-21

    The reaction of a nickelalactone with dppm, resulting in the formation of a stable binuclear Ni(I) complex with an acrylate, a Ph2P- and a dppm bridge, models a key step in the formation of acrylic acid from CO2 and ethylene.

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

    Science.gov (United States)

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

  5. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Science.gov (United States)

    Zakrevskyy, Yuriy; Cywinski, Piotr; Cywinska, Magdalena; Paasche, Jens; Lomadze, Nino; Reich, Oliver; Löhmannsröben, Hans-Gerd; Santer, Svetlana

    2014-01-01

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes' properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate - for the first time - complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  6. Radiation-induced synthesis of poly(acrylic acid) nanogels

    Science.gov (United States)

    Matusiak, Malgorzata; Kadlubowski, Slawomir; Ulanski, Piotr

    2018-01-01

    Nanogel is a two-component system of a diameter in the range of tens of nanometers, consisting of an intramolecularly crosslinked polymer chain and solvent, typically water, filling the space between segments of the macromolecule. Microgels are bigger than nanogels and their size range is between 100 nm to 100 μm. One of the methods used for synthesizing nanogels is linking the segments of a single macromolecule with the use of ionizing radiation, by intramolecular recombination of radiation-generated polymer radicals. The main advantage of this technique is absence of monomers, catalysts, surfactants or crosslinking agents. This method is an interesting alternative way of synthesizing polymeric carriers for biomedical applications. The aim of the study was radiation synthesis and characterization of poly(acrylic acid) - PAA - nanogels and microgels. The physico-chemical properties were described by determination of weight-average molecular weight and dimensions (radius of gyration, hydrodynamic radius) of the nanogels and microgels. Influence of polymer concentration and dose on these parameters was analyzed. Adjusting the PAA concentration and absorbed dose, one can control the molecular weight and dimensions of nanogels. The solutions of PAA were irradiated with two sources of ionizing radiation: γ-source and electron accelerator. The former method yields mainly microgels due to prevailing intermolecular crosslinking, while the latter promotes intramolecular recombination of PAA-derived radicals and in consequence formation of nanogels. In the future radiation-synthesized PAA nanogels, after functionalization, will be tested as carriers for delivering radionuclides to the tumor cells.

  7. Acrylic acid derivatives of group 8 metal carbonyls: a structural and kinetic study.

    Science.gov (United States)

    Li, Bo; Kyran, Samuel J; Yeung, Andrew D; Bengali, Ashfaq A; Darensbourg, Donald J

    2013-05-06

    The synthesis, spectroscopic, and X-ray structural studies of acrylic acid complexes of iron and ruthenium tetracarbonyls are reported. In addition, the deprotonated η(2)-olefin bound acrylic acid derivative of iron as well as its alkylated species were fully characterized by X-ray crystallography. Kinetic data were determined for the replacement of acrylic acid, acrylate, and methylacrylate for the group 8 metal carbonyls by triphenylphosphine. These processes were found to be first-order in the concentration of metal complex with the rates for dissociative loss of the olefinic ligands from ruthenium being much faster than their iron analogues. However, the ruthenium derivatives afforded formation of primarily mono-phosphine metal tetracarbonyls, whereas the iron complexes led largely to trans-di-phosphine tricarbonyls. This difference in behavior was ascribed to a more stable spin crossover species (3)Fe(CO)4 which undergoes rapid CO loss to afford the bis phosphine derivative. The activation enthalpies for dissociative loss of the deprotonated η(2)-bound acrylic acid ligand were found to be larger than their corresponding values in the protonated derivatives. For example, for dissociative loss of the protonated and deprotonated acrylic acid derivatives of iron(0) the ΔH(‡) values determined were 28.0 ± 1.2 and 34.1 ± 1.5 kcal·mol(-1), respectively. Density functional theory (DFT) computations of the bond dissociation energies (BDEs) in these acrylic acids and closely related complexes were in good agreement with enthalpies of activation for these ligand substitution reactions, supportive of a dissociative mechanism for olefin displacement. Processes related to catalytic production of acrylic acid from CO2 and ethylene are considered.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

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

  9. Supercritical water oxidation of acrylic acid production wastewater.

    Science.gov (United States)

    Gong, Y M; Wang, S Z; Tang, X Y; Xu, D H; Ma, H H

    2014-01-01

    Supercritical water oxidation (SCWO) of wastewater from an acrylic acid manufacturing plant has been studied on a continuous flow experimental system, whose reactor was made of Hastelloy C-276. Experimental conditions included a reaction temperature (T) ranging from 673 to 773K, a residence time (t) ranging from 72.7 to 339s, a constant pressure (P) of 25 MPa and a fixed oxidation coefficient (alpha) of 2.0. Experimental results indicated that reaction temperature and residence time had significant influences on the oxidation reaction, and increasing the two operation parameters could improve both degradation of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). The COD removal efficiency could reach up to 98.73% at 25 MPa, 773 K and 180.1 s, whereas the destruction efficiency of NH3-N was only 43.71%. We further carried out a kinetic analysis considering the induction period through free radical chain mechanism. It confirms that the power-law rate equation for COD removal was 345 exp(-52200/RT)[COD]1.98[O2]0.17 and for NH3-N removal was 500 exp(-64492.19/RT)[NH3-N]1.87 [O2]0.03. Moreover, the induction time formulations for COD and NH3-N were suspected to be exp(38250/RT)/173 and exp(55690/RT)/15231, respectively. Correspondingly, induction time changed from 2.22 to 5.38 s for COD and 0.38 to 1.38 s for NH3-N. Owing to the catalysis of reactor inner wall surface, more than 97% COD removal was achieved in all samples.

  10. The synthesis of fatty acid ethyl ester by carboxylester lipase.

    Science.gov (United States)

    Tsujita, T; Okuda, H

    1994-08-15

    Carboxylester lipase obtained from pig pancreas is associated with fatty acid ethyl ester synthase as judged by their elution in the same fraction from a heparin-Sepharose column, coprecipitations by antibody against purified carboxylester lipase and identical profiles of inhibition by diisopropyl fluorophosphate. Only one polypeptide of molecular mass 74-kDa in purified carboxylester lipase was labeled by immunostaining and affinity labeling with [3H]diisopropyl fluorosphate. Bovine serum albumin decreased the fatty-acid-ethyl-ester-synthesizing activity in a concentration-dependent manner. On incubation of purified carboxylester lipase with trioleylglycerol in an ethanol/water mixture, fatty acid ethyl ester was formed in the presence of a high concentration of bovine serum albumin. The acyltransfer activities from trioleylglycerol to ethanol (ethanolysis) were approximately 25-30 times higher than the acyltransfer activities to water (hydrolysis). When cholesterol was used as an acceptor, acyltransfer activity from trioleylglycerol to cholesterol (cholesterolysis) was also observed. We propose the following mechanism of fatty acid ethyl ester formation from triacyl glycerol. The enzyme attacks triacyl glycerol forming an acyl-enzyme intermediate, and during the deacylation process, alcohol binds to fatty acid as an acceptor. These results suggest that during lipid (triacyl glycerol) degradation, carboxylester lipase contributes to non-oxidative ethanol metabolism in the intestinal lumen.

  11. Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

    DEFF Research Database (Denmark)

    Oswald, Iain D. H.; Urquhart, Andrew J.

    2011-01-01

    The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar...

  12. Growth inhibitory properties of lactose fatty acid esters

    Directory of Open Access Journals (Sweden)

    Seung-Min Lee

    2017-11-01

    Full Text Available Sugar esters are biodegradable, nonionic surfactants which have microbial inhibitory properties. The influence of the fatty acid chain length on the microbial inhibitory properties of lactose esters was investigated in this study. Specifically, lactose monooctanoate (LMO, lactose monodecanoate (LMD, lactose monolaurate (LML and lactose monomyristate (LMM were synthesized and dissolved in both dimethyl sulfoxide (DMSO and ethanol. Minimum inhibitory concentrations (MIC and minimum bactericidal concentrations (MBC were determined in growth media. LML was the most effective ester, exhibiting MIC values of <0.05 to <5 mg/ml for each Gram-positive bacteria tested (Bacillus cereus, Mycobacterium KMS, Streptococcus suis, Listeria monocytogenes, Enterococcus faecalis, and Streptococcus mutans and MBC values of <3 to <5 mg/ml for B. cereus, M. KMS, S. suis, and L. monocytogenes. LMD showed MIC and MBC values of <1 to <5 mg/ml for B. cereus, M. KMS, S. suis, L. monocytogenes, and E. faecalis, with greater inhibition when dissolved in ethanol. LMM showed MIC and MBC values of <1 to <5 mg/ml for B. cereus, M. KMS, and S. suis. LMO was the least effective showing a MBC value of <5 mg/ml for only B. cereus, though MIC values for S. suis and L. monocytogenes were observed when dissolved in DMSO. B. cereus and S. suis were the most susceptible to the lactose esters tested, while S. mutans and E. faecalis were the most resilient and no esters were effective on Escherichia coli O157:H7. This research showed that lactose esters esterified with decanoic and lauric acids exhibited greater microbial inhibitory properties than lactose esters of octanoate and myristate against Gram-positive bacteria.

  13. The role of acrylic acid impurity as a sensitizing component in electrocardiogram electrodes.

    Science.gov (United States)

    Stingeni, Luca; Cerulli, Emilia; Spalletti, Anna; Mazzoli, Alessandra; Rigano, Luigi; Bianchi, Leonardo; Hansel, Katharina

    2015-07-01

    Allergic contact dermatitis caused by (meth)acrylates is well known, both in occupational and in non-occupational settings. Contact hypersensitivity to electrocardiogram (ECG) electrodes containing (meth)acrylates is rarely reported. To report the first case of contact dermatitis caused by acrylic acid impurity in ECG electrodes. Patch tests were performed with separate components of electrodes and some (meth)acrylates. This was followed by high-performance liquid chromatography of electrode hydrogel. The patient was contact-allergic to electrode hydrogel but not to its separate constituents. Positive reactions were observed to 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxypropyl methacrylate (2-HPMA) and ethyleneglycol dimethacrylate (EGDMA). Subsequent analysis showed that the electrode hydrogel contained acrylic acid as an impurity. The latter was subsequently patch tested, with a positive result. The sensitization resulting from direct contact with ECG electrodes was caused by acrylic acid, present as an impurity in ECG electrodes. Positive reactions to 2-HEMA, 2-HPMA and EGDMA are considered to be cross-reactions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Effect of a novel insulinotropic agent, succinic acid monoethyl ester ...

    Indian Academy of Sciences (India)

    Madhu

    artery disease such as hypertension, obesity and dyslipidemia. Effect of a novel insulinotropic agent, succinic acid monoethyl ester, on lipids and lipoproteins levels in rats with streptozotocin-nicotinamide- induced type 2 diabetes. RAMALINGAM SARAVANAN and LEELAVINOTHAN PARI*. Department of Biochemistry and ...

  15. In vitro pharmacokinetics of anti-psoriatic fumaric acid esters

    NARCIS (Netherlands)

    N.H.R. Litjens (Nicolle); E. van Strijen (Elizabeth); C. van Gulpen (Co); H. Mattie (Herman); J.T. van Dissel (Jaap); H.B. Thio (Bing); P.H. Nibbering (Peter)

    2004-01-01

    textabstractBackground: Psoriasis is a chronic inflammatory skin disease that can be successfully treated with a mixture of fumaric acid esters (FAE) formulated as enteric-coated tablets for oral use. These tablets consist of dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) and its main

  16. Synthesis of radiation crosslinked poly(acrylic acid) in the presence of phenyltriethoxysilane

    Science.gov (United States)

    Hassan, Safia; Yasin, Tariq

    2014-04-01

    Acrylic acid based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as polyfunctional monomer. Different amounts of PTES were incorporated in acrylic acid and irradiated at different doses upto maximum of 30 kGy. The crosslinked acrylic acid showed hydrogel properties and its swelling kinetics, gel fraction and equilibrium degree of swelling (EDS) were studied. It was found that the increased PTES concentration decreased the EDS of the hydrogels. Infrared spectroscopy confirmed the crosslinking reaction between the feed components and the existence of siloxane bond. Thermogravimetric analysis showed an increase in the stability of the hydrogels having high PTES content. The swelling of the hydrogel was affected by pH, ionic strength and temperature. These hydrogels showed low swelling in acidic and basic pH range and high swelling around neutral pH. This switchable pH response of these hydrogels can be exploited in environmental and biomedical applications.

  17. Temperature dependence of the heterogeneous uptake of acrylic acid on Arizona test dust.

    Science.gov (United States)

    Liu, Qifan; Wang, Yidan; Wu, Lingyan; Jing, Bo; Tong, Shengrui; Wang, Weigang; Ge, Maofa

    2017-03-01

    In this study, the temperature dependence of the heterogeneous uptake of acrylic acid on Arizona test dust (ATD) has been investigated within a temperature range of 255-315K using a Knudsen cell reactor. Combined with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiment, it was found that acrylic acid could adsorb on ATD via surface OH groups and convert to carboxylate on the particle surface. The kinetics study suggests that the initial true uptake coefficient (γt) of acrylic acid on ATD decreases from (4.02±0.12)×10(-5) to (1.73±0.05)×10(-5) with a temperature increase from 255 to 315K. According to the temperature dependence of uptake coefficients, the enthalpy (ΔHobs) and entropy (ΔSobs) of uptake processes were determined to be -(9.60±0.38) KJ/mol and -(121.55±1.33) J·K/mol, respectively. The activation energy for desorption (Edes) was calculated to be (14.57±0.60) KJ/mol. These results indicated that the heterogeneous uptake of acrylic acid on ATD surface was sensitive to temperature. The heterogeneous uptake on ATD could affect the concentration of acrylic acid in the atmosphere, especially at low temperature. Copyright © 2016. Published by Elsevier B.V.

  18. Encapsulating fatty acid esters of bioactive compounds in starch

    Science.gov (United States)

    Lay Ma, Ursula Vanesa

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

  19. Transformation of Unsaturated Fatty Acids/Esters to Corresponding Keto Fatty Acids/Esters by Aerobic Oxidation with Pd(II)/Lewis Acid Catalyst.

    Science.gov (United States)

    Senan, Ahmed M; Zhang, Sicheng; Zeng, Miao; Chen, Zhuqi; Yin, Guochuan

    2017-08-16

    Utilization of renewable biomass to partly replace the fossil resources in industrial applications has attracted attention due to the limited fossil feedstock with the increased environmental concerns. This work introduced a modified Wacker-type oxidation for transformation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, in which Cu2+ cation was replaced with common nonredox metal ions, that is, a novel Pd(II)/Lewis acid (LA) catalyst. It was found that adding nonredox metal ions can effectively promote Pd(II)-catalyzed oxidation of unsaturated fatty acids/esters to the corresponding keto fatty acids/esters, even much better than Cu2+, and the promotional effect is highly dependent on the Lewis acidity of added nonredox metal ions. The improved catalytic efficiency is attributed to the formation of heterobimetallic Pd(II)/LA species, and the oxidation mechanism of this Pd(II)/LA catalyst is also briefly discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-07

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

  2. PROCESS FOR HYDROGENOLYSIS OF ALPHA-HYDROXY ESTERS OR ACIDS USING A HETEROGENEOUS CATALYST

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to a method for hydrogenolysis of alpha-hydroxy esters or acids, comprising reacting the alpha-hydroxy ester or acid in the presence of a heterogeneous catalyst. The present invention also relates to a method for producing propionic acid ester, and the use of any...

  3. 75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption

    Science.gov (United States)

    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...

  4. 21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true 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...

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

    Science.gov (United States)

    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. Synthesis of a novel acrylated abietic acid-g-bacterial cellulose hydrogel by gamma irradiation.

    Science.gov (United States)

    Abeer, Muhammad Mustafa; Amin, Mohd Cairul Iqbal Mohd; Lazim, Azwan Mat; Pandey, Manisha; Martin, Claire

    2014-09-22

    Acrylated abietic acid (acrylated AbA) and acrylated abietic acid-grafted bacterial cellulose pH sensitive hydrogel (acrylated AbA-g-BC) were prepared by a one-pot synthesis. The successful dimerization of acrylic acid (AA) and abietic acid (AbA) and grafting of the dimer onto bacterial cellulose (BC) was confirmed by 13C solid state NMR as well as FT-IR. X-ray diffraction analysis showed characteristic peaks for AbA and BC; further, there was no effect of increasing amorphous AA content on the overall crystallinity of the hydrogel. Differential scanning calorimetry revealed a glass transition temperature of 80°C. Gel fraction and swelling studies gave insight into the features of the hydrogel, suggesting that it was suitable for future applications such as drug delivery. Scanning electron microscopy observations showed an interesting interpenetrating network within the walls of hydrogel samples with the lowest levels of AA and gamma radiation doses. Cell viability test revealed that the synthesized hydrogel is safe for future use in biomedical applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Directory of Open Access Journals (Sweden)

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  8. Evaluation of Liquid-Liquid Extraction Process for Separating Acrylic Acid Produced From Renewable Sugars

    Science.gov (United States)

    Alvarez, M. E. T.; Moraes, E. B.; Machado, A. B.; Maciel Filho, R.; Wolf-Maciel, M. R.

    In this article, the separation and the purification of the acrylic acid produced from renewable sugars were studied using the liquid-liquid extraction process. Nonrandom two-liquids and universal quasi-chemical models and the prediction method univeral quasi-chemical functional activity coefficients were used for generating liquid-liquid equilibrium diagrams for systems made up of acrylic acid, water, and solvents (diisopropyl ether, isopropyl acetate, 2-ethyl hexanol, and methyl isobutyl ketone) and the results were compared with available liquid-liquid equilibrium experimental data. Aspen Plus (Aspen Technology, Inc., version 2004.1) software was used for equilibrium and process calculations. High concentration of acrylic acid was obtained in this article using diisopropyl ether as solvent.

  9. Radiation synthesis of superabsorbent poly(acrylic acid)-carrageenan hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju; Kumar, Manmohan; Varshney, Lalit E-mail: lalitv@magnum.barc.ernet.in

    2004-04-01

    A series of superabsorbent hydrogels were prepared from carrageenan and partially neutralized acrylic acid by gamma irradiation at room temperature. The gel fraction, swelling kinetics and the equilibrium degree of swelling (EDS) of the hydrogels were studied. It was found that the incorporation of even 1% carrageenan (sodium salt) increases the EDS of the hydrogels from {approx}320 to {approx}800 g/g. Thermal analysis were carried out to determine the amount of free water and bound water in the hydrogels. Under optimum conditions, poly(acrylic acid)-carrageenan hydrogels with high gel fraction ({approx}80%) and very high EDS ({approx}800 g/g) were prepared gamma radiolytically from aqueous solution containing 15% partially neutralized acrylic acid and 1-5% carrageenan. The hydrogels were also found to be sensitive to the pH and the ionic strength of the medium.

  10. Conversion of carbohydrates to levulinic acid esters

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass...

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

    OpenAIRE

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

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant E...

  12. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    Directory of Open Access Journals (Sweden)

    Keslarek Amauri José

    2004-01-01

    Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

  13. Acrylic acid surface-modified contact lens for the culture of limbal stem cells.

    Science.gov (United States)

    Zhang, Hong; Brown, Karl David; Lowe, Sue Peng; Liu, Guei-Sheung; Steele, David; Abberton, Keren; Daniell, Mark

    2014-06-01

    Surface treatment to a biomaterial surface has been shown to modify and help cell growth. Our aim was to determine the best surface-modified system for the treatment of limbal stem cell deficiency (LSCD), which would facilitate expansion of autologous limbal epithelial cells, while maintaining cultivated epithelial cells in a less differentiated state. Commercially available contact lenses (CLs) were variously surface modified by plasma polymerization with ratios of acrylic acid to octadiene tested at 100% acrylic acid, 50:50% acrylic acid:octadiene, and 100% octadiene to produce high-, mid-, and no-acid. X-ray photoelectron spectroscopy was used to analyze the chemical composition of the plasma polymer deposited layer. Limbal explants cultured on high acid-modified CLs outgrew more cells. Immunofluorescence and RT2-PCR array results indicated that a higher acrylic acid content can also help maintain progenitor cells during ex vivo expansion of epithelial cells. This study provides the first evidence for the ability of high acid-modified CLs to preserve the stemness and to be used as substrates for the culture of limbal cells in the treatment of LSCD.

  14. Screening of Catalyst and Important Variable for The Esterification of Acrylic Acid with 2 Ethylhexanol

    Science.gov (United States)

    Ahmad, M. A. A.; Chin, S. Y.

    2017-06-01

    The global demand of 2-ethylhexyl acrylate (2EHA) market has witnessed a significant growth in the past few years and this growth is anticipated to increase in the coming years. 2EHA is one of the basic organic building blocks that mainly used in the production of coatings, adhesives, superabsorbents, thickeners and plastic additives. Homogenous acid-catalysed esterification of acrylic acid (AA) with 2-ethylhexanol (2EH) is commonly used for the production of 2EHA. The homogeneous catalysts such as sulfuric and para-toluene sulfonic acid have resulted the costly and complicated downstream process that generates acidic, corrosive and non-environmental friendly waste. Therefore, it is importance to develop a cheaper process that employing heterogeneous catalysts and alternative raw material from wastewater containing acrylic acid. In this research, the study for the esterification of AA with 2EH catalysed by ion-exchange resin was conducted. The best sulfonic acid functional cation-exchange resin among SK104, SK1B, PK208, PK216, PK228, RCP145, and RCP160 was screened. PK208 outperformed the other resins and it was used subsequently in the parametric studies. The effect of important parameters (initial concentration of acrylic acid (AA), temperature, molar ratio of reactant (AA and 2EH), catalyst loading, and polymerisation inhibitor loading) was studied using 2 factorial design to determine the significant parameters to the esterification. It was found that the initial concentration of AA and temperature were most significantly affecting the esterification of AA with 2EH.

  15. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  16. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan

    OpenAIRE

    Hortensia Ortega-Ortiz; Baltazar Gutiérrez-Rodríguez; Gregorio Cadenas-Pliego; Luis Ibarra Jimenez

    2010-01-01

    The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 pr...

  17. Substituted esters of stearic acid as potential lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Kleinova, Andrea; Fodran, Peter; Brncalova, Lucia; Cvengros, Jan [Department of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, SK-812 37 Bratislava (Slovakia)

    2008-04-15

    Preparation and properties of four triesters - derivatives of 9,10-dihydroxystearic acid after the epoxidation of methyl ester of the oleic acid, opening of the formed oxirane ring in suitable medium and esterification of free hydroxyl group is discussed in the paper. Removal of the double bond from acyl of the fatty acid, increase of the molar weight and change of molecular structure resulted in increase of viscosity and oxidation stability of prepared triesters. Lubrication tests performed on a four-ball machine showed better tribological characteristics of synthesized triesters when compared with mineral additive-free base oil. (author)

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

    Science.gov (United States)

    Deegan, Alexander Paul; Kirby, Brian; Rogers, Sarah; Crotty, Tom Bernard; McDonnell, Timonthy John

    2010-10-01

      We present the case of a 49-year old male who presented with dyspnoea, cough, weight loss, night sweats and general malaise. He had been on treatment with oral fumaric acid esters (FAE, Fumaderm®; Biogen Idec GmbH, Ismaning, Germany) for 6 months.   Report of a case.   His chest X-ray showed patchy infiltrates in the left upper lobe which failed to resolve under empiric antibiotic therapy. A computed tomography of thorax revealed bilateral, mostly peripheral foci of consolidation with air bronchograms. Transbronchial biopsies showed a pattern of organising pneumonia (OP).   Therapy with oral prednisolone (40 mg/day) resulted in a rapid clinical and radiological improvement. An association of FAE and OP has not previously been reported. Please cite this paper as: Deegan AP, Kirby B, Rogers S, Crotty TB and McDonnell TJ. Organising pneumonia associated with fumaric acid ester treatment for psoriasis. © 2010 Blackwell Publishing Ltd.

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

    LENUS (Irish Health Repository)

    Deegan, Alexander Paul

    2012-02-01

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

  20. Electroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  1. Thin film of Poly(acrylic acid-co-allyl acrylate as a Sacrificial Protective Layer for Hydrophilic Self Cleaning Glass

    Directory of Open Access Journals (Sweden)

    Jānis Lejnieks

    2010-05-01

    Full Text Available Poly(acrylic acid-co-allyl acrylate statistical copolymers were synthesized in a controlled manner in two steps: first tert.butyl acrylate and allyl acrylate were polymerized via atom transfer radical polymerization (ATRP and afterwords the tert.butyl protective groups were removed via hydrolysis. Samples of self cleaning glass (SCG were coated with thin films of poly(acrylic acid-co-allyl acrylate and cross-linked afterwards by UV irradiation (in the presence of a photoinitiator and an accelerator. Solution cast thin films were transparent and homogeneous before and after UV cross-linking. The irradiated samples were found to be hydrophilic (Θ < 20° and water insoluble. The coating prevented the spontaneous hydrophobization of the SCG by residual silicon exhaled from the sealing material. The TiO2 photocatalyst that covers the glass surface was found to strip the protective coating. The rate of the photooxidation process was measured by IR spectroscopy. The real field performance of the protective coating was also tested.

  2. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Directory of Open Access Journals (Sweden)

    Stojanović Marija M.

    2013-01-01

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

  3. Fumaric acid esters in the management of psoriasis

    OpenAIRE

    Balak DMW

    2015-01-01

    Deepak MW Balak Department of Dermatology, Erasmus Medical Center, Rotterdam, the Netherlands Abstract: Fumaric acid esters (FAE) are small molecules with immunomodulating, anti-inflammatory, and anti-oxidative effects. FAE were introduced as a systemic psoriasis treatment in 1959 and empirically developed further between 1970 and 1990 in Germany, Switzerland, and the Netherlands. The development of FAE as psoriasis treatment did not follow the traditional drug development phases. Nonetheles...

  4. 40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid polyamine condensate, phosphoric acid ester salts. 721.6200 Section 721.6200 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.6200 Fatty acid polyamine condensate, phosphoric acid...

  5. Poly(acrylic acid) to induce competitive crystallization of a theophylline/oxalic acid cocrystal and a theophylline polymorph

    Science.gov (United States)

    Jang, Jisun; Kim, Il Won

    2016-01-01

    Polymeric additives to induce competitive crystallization of pharmaceutical compounds were explored. A cocrystal of theophylline and oxalic acid was used as a model system, and poly(acrylic acid), poly(caprolactone), and poly(ethylene glycol) were the additives. The cocrystal formation was selectively hindered with addition of poly(acrylic acid). First the size of the cocrystals were reduced, and eventually the cocrystallization was inhibited to generate neat theophylline crystals. The theophylline crystals were of a distinctively different crystal structure from known polymorphs, based on powder X-ray diffraction. They were also obtained in nanoscale size, when millimeter-scale crystals formed without poly(acrylic acid). Polymeric additives that could form specific interactions with crystallizing compounds seem to be useful tools for the phase and size control of pharmaceutical crystals.

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

    Science.gov (United States)

    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.

  7. The Zinc Mediated Condensation of Amino Acid Esters with Imines to b-Lactams

    NARCIS (Netherlands)

    Koten, G. van; Jastrzebski, J.T.B.H.

    1993-01-01

    An experimentally attractive stereoselectie 'one pot' synthesis of beta-lactams is described. This route is based on the zinc mediated condensation of an alpha-amino acid ester with an imine via a zinc ester enolate. Making use of proper substituents in both the amino acid ester and the imine the

  8. An effective method and pathways of acrylonitrile degradation to acrylic acid through an alkaline hydrothermal system.

    Science.gov (United States)

    Dong, Wenjie; Peng, Boyu; Wang, Ke; Miao, Jia; Zhang, Wei; Zhang, Yalei; Shen, Zheng

    2017-07-01

    Degradation of pollution for specific chemicals represents an optimal approach to high-strength wastewater treatment. One-pot selective conversion of acrylonitrile to acrylic acid in a hydrothermal system with NaOH as a catalyst was carried out. The influence factors were evaluated, including initial acrylonitrile concentration, reaction temperature, reaction time and amount of alkali. Experimental results showed that the highest yield of acrylic acid (55%) was obtained at the initial acrylonitrile concentration of 3 × 10(3) mg/L, 300°C for 90 s with 1.0 M NaOH. To determine the reaction path, intermediates analysis and calculation of carbon and nitrogen balance were carried out by means of HPLC, GC and TOC/TN methods. Two probable reaction pathways were proposed as follows: (1) Acrylonitrile was hydrolyzed into acrylamide, and acrylic acid was obtained via further hydrolysis. (2) Acrylonitrile was converted into 3-hydroxy-propionitrile via additive reaction, and this product was readily converted to 3-hydroxy-propionic acid through two steps of hydrolysis, followed by dehydration reaction to produce acrylic acid. This study offered not only an efficient method to transfer highly toxic pollutants into valuable chemical, but also a better understanding of hydrothermal alkali catalytic reaction.

  9. Synthesis of Poly(styrene-acrylates-acrylic acid Microspheres and Their Chemical Composition towards Colloidal Crystal Films

    Directory of Open Access Journals (Sweden)

    Luis A. Ríos-Osuna

    2016-01-01

    Full Text Available In this paper, polystyrene colloidal microspheres have been prepared using hexyl acrylate (HA, ethylhexyl acrylate (EHA, isooctyl acrylate (IOA, butyl acrylate (BA, or isobutyl acrylate (IBA as comonomers. Microspheres with diameters from 212 to 332 nm and with a polystyrene content of 65–78% were prepared. The particles prepared in this work do not present the typical core-shell structure; as a consequence, DSC analysis showed that the microspheres exhibited only one Tg. TEM images show that the particles with comonomer content below ~30% were spherical and regular. Microspheres containing comonomer between 21 to 25% produced the less brittle films showing very iridescent colors. The films prepared from microspheres containing hexyl, ethylhexyl, and isooctyl acrylate as comonomers are firmly attached to the substrate due to their adhesive properties. The large decrease of the fragility observed in these films makes them much more attractive materials in sensing applications.

  10. Bio-based acrylic acid from sugar via propylene glycol and allyl alcohol

    NARCIS (Netherlands)

    Pramod, C. V.; Fauziah, R.; Seshan, K.; Lange, J. P.

    2018-01-01

    A new route for producing bio-based acrylic acid is proposed. It starts with the conversion of carbohydrates to propylene glycol, being main or by-product, and proceeds via a subsequent dehydration to allyl alcohol under gas-phase conditions over K-modified ZrO2 and a final oxidation over MoWVOx

  11. 40 CFR 721.321 - Substituted acrylamides and acrylic acid copolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant... identified generically as substituted acrylamides and acrylic acid copolymer (PMN P-00-0490) is subject to... of this part apply to this section except as modified by this paragraph. (1) Recordkeeping...

  12. Dielectric properties of solution-grown-undoped and acrylic-acid ...

    Indian Academy of Sciences (India)

    Dielectric capacities and losses were measured, in the temperature (50–170°C) and frequency (01–100 kHz range), for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 m) with progressive increase in the concentration of dopant in the polymer matrix. The variation of capacity with ...

  13. Bioconversion of acrylonitrile to acrylic acid by rhodococcus ruber strain AKSH-84.

    Science.gov (United States)

    Kamal, Ahmed; Kumar, M Shiva; Kumar, C Ganesh; Shaik, Thokhir

    2011-01-01

    A new versatile acrylonitrile-bioconverting strain isolated from a petroleum-contaminated sludge sample and identified as Rhodococcus ruber AKSH-84 was used for optimization of medium and biotransformation conditions for nitrilase activity to produce acrylic acid. A simple and rapid HPLC protocol was optimized for quantification of acrylic acid, acrylamide, and acrylonitrile. The optimal medium conditions for nitrilase activity were pH of 7.0, temperature of 30degreesC, agitation of 150 rpm, and inoculum level of 2%. Glycerol as a carbon source and sodium nitrate as the nitrogen source provided good nutritional sources for achieving good biotransformation. Nitrilase activity was constitutive in nature and was in the exponential growth phase after 24 h of incubation under optimal conditions without addition of any inducer. The substrate preference was acrylonitrile and acetonitrile. The present work demonstrates the biotransformation of acrylonitrile to acrylic acid with the new strain, R. ruber AKSH-84, which can be used in green biosynthesis of acrylic acid for biotechnological processes. The nitrilase produced by the isolate was purified and characterized.

  14. Application of lipase technology for transesterification of fatty acid ester

    Directory of Open Access Journals (Sweden)

    JOKO SULISTYO

    2005-07-01

    Full Text Available We have reported the potency of microbial extracellular enzyme for synthesis of fatty acid ester. Further investigation was aimed to study capacity of the enzyme on bioprocess of crude palm oil by transesterification of saturated fatty acid to fatty acid ester. We have studied some lipases from culture filtrate of Candida rugosa FM-9301, Bacillus subtilis FM-9101 and Pseudomonas aerogenes FM-9201, which were preincubated in a medium containing olive oil as inducers, using a shaker under conditions that allowed for lipase production at pH 4.5-6.5 and room temperature for 5 days. Those strains shown different activities during the hydrolysis of substrates, which resulted in decreasing or increasing free fatty acids those, were liberated from media containing crude palm oil and organic solvents. The optimal transesterification condition was at temperature of 45-50C and at pH 4.5 for C. rugosa and pH 6.0 to 7.0 for P. aerogenes and B. subtilis. Under the enzyme concentration of 50% (v/v, the transesterification was rapidly occurred, while at the concentration of 20% (v/v the enzymatically biosynthesis required longer incubation period. The substrates incubated with C. rugosa lipase exhibited higher linoleic and linolenic acid (7.16 and 2.15%, respectively, than that of B. subtilis lipase (4.85% and 1.43%, respectively, while P. aerogenes lipase (3.73% and 1.11%, respectively.

  15. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional......) of tent-butyl acrylate (tBA) in a controlled fashion by use of NiBr2(PPh3)(2) catalyst to produce Prot-PCL-b-PtBA with narrow polydispersities (1.17-1.39). Subsequent mild deprotection protocols provided HS-PCL-b-PAA. Reduction of a gold salt in the presence of this macroligand under thiol...

  16. Eco-friendly Crosslinking Agent for Acid Functional Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Archana Shah

    2009-01-01

    Full Text Available Oil from J. multifida was extracted and it was first converted into N,N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA. HEJFA has been synthesized by reaction between Jatropha oil and diethanol amine in presence of zinc oxide as a catalyst. The reaction is relatively rapid and proceeded to high yield at 200±5 OC. The resulting HEJFA was used to formulate thermosetting coating compositions. Films were cured at ambient (air drying and elevated (stove drying temperatures using N, N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA as eco-friendly crosslinking agent for acrylic resin. The coating performance of the various compositions was tested by measurement of scratch hardness, impact strength and chemical resistance. The results show better performance of the HEJFA based compositions compared to butylated melamine formaldehyde (MF based compositions.

  17. Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

    Science.gov (United States)

    Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

    2014-05-12

    The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

  18. Synthesis of dense poly(acrylic acid) brushes and their interaction with amine-functional silsesquioxane nanoparticles

    NARCIS (Netherlands)

    Retsch, Markus; Walther, Andreas; Loos, Katja; Mueller, Axel H. E.; Müller, Axel H.E.

    2008-01-01

    Poly(acrylic acid) polyetectrolyte brushes were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP) of tert-butyl acrylate on planar gold surfaces and subsequent hydrolysis. Three types of monolayers with different numbers of thiol binding sites per initiating unit were

  19. Production of Oleic Acid Based Wax Ester Using Acidic Homogeneous Catalysts

    Directory of Open Access Journals (Sweden)

    Naowara Al-Arafi

    2012-01-01

    Full Text Available Four homogeneous acidic catalysts were tested for their ability to catalyze the esterification reaction of oleic acid and oleyl alcohol to produce oleyl oleate, a wax ester. Sulfuric acid showed relatively higher specific activity. Various reaction parameters were optimised to obtain high percentage yield of oleyl oleate. The optimum condition to produce oeyl oleate was reaction time; 5 h, temperture; 90°C, amount of sulforic acid 0.15 g and molar ratio of oleyl alcohol to oleic acid; 1:1. Percentage yield of wax ester obtained at these optimum reaction conditions was 93.88. Disappearance of carboxylic acid (C=O peak has confirmed by FTIR with appearance of ester (C=O peak at 1739 cm−1. 1H NMR spectra analyses confirmed the result of oleyl oleate with appearance of ester (-CH2OCOR at 4.02 ppm and also the 13C-NMR confirmed the result with appearance of ester (C=O peak at 173.2 ppm. The low-temperture behavior of compound synthesized was determined through its pour point (PP, viscosity index (VI and flash point (FP values. The results showed that oleyl oleate exhibited the most favorable low-temperture performance of PP, VI and FP with −31°C, 197.5 and 320°C respectively. This is due to increase of the molacular weight thus improve the low temperture property significantly.

  20. Fluconazole release from hydrogels including acrylamide-acrylic acid-itaconic acid, and their microbiological interactions.

    Science.gov (United States)

    Pulat, Mehlika; Eksi, Haslet; Abbasoglu, Ufuk

    2008-01-01

    Polyacrylamide (PAAm), polyacrylic acid (PAA), poly(acrylamide-co-itaconic acid) (PAAmIA) and poly(acrylic acid-co-itaconic acid) (PAAIA) hydrogels were prepared via free-radical polymerization using ethylene glycol dimethacrylate (EGDMA) as cross-linker. The variations of swelling percentages with time and pH were determined for these hydrogels at 37 degrees C. PAAmIA was found as the most swollen hydrogel at pH 4.0. SEM micrographs were taken to observe the morphology of the hydrogels. The less swollen hydrogel, PAAIA, displays less porosity relative to PAAmIA hydrogel. Fluconazole was entrapped into PAAmIA and PAAIA hydrogels and the release was investigated in Britton-Robinson buffer solution (BR) at pH 4.0 and 37 degrees C. The kinetic release parameters of the hydrogels, n and k, were calculated and Fickian-type diffusion was established for PAAmIA, which releases Fluconazole faster than PAAIA hydrogel. Therapeutic range was reached in the first hour for both hydrogels. Microbiological interactions of hydrogels were also studied in vitro in vaginal medium. It is found that Fluconazole entrapped in hydrogels inhibited the growth of Candida albicans.

  1. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

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

    Science.gov (United States)

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

  3. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  4. Organocopper reactions with allylic acrylates. The preparation of {gamma},{delta}-unsaturated acids and the subsequent transformation to {gamma}-lactones

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, M.; Nilsson, M.; Olsson, T. [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1995-12-31

    The conjugate addition of organocopper reagents to {alpha},{beta}-unsaturated ketones and esters is a commonly used method for carbon-carbon bond formation. When this is applied on allylic enoates, the primary ester enolates/silyl ketene acetals from the addition undergo Claisen rearrangement at room temperature to afford diastereomeric mixtures of {gamma},{delta}-unsaturated acids after hydrolytic work-up. The E/Z ratio for the primary ester enolates/silyl ketene acetals controls the erythro:threo ratio for the {gamma},{delta}-unsaturated acids. The present work is an investigation of different organocopper reagents (e.g. RCu(LiI)-TMSI) in reactions with crotyl and cinnamyl acrylate. The diastereomeric ratio is strongly influenced by the organocopper reagent (RCu(LiI) vs R{sub 2}CuLi(LiI)) as well as the additive (TMSCl vs TMSI). Subsequent iodolactonization of the {gamma},{delta}-unsaturated acids followed by reduction give trisubstituted {gamma}-lactones in good overall yields.

  5. gamma-Aminobutyric acid esters. 2. Synthesis, brain uptake, and pharmacological properties of lipid esters of gamma-aminobutyric acid.

    Science.gov (United States)

    Jacob, J N; Shashoua, V E; Campbell, A; Baldessarini, R J

    1985-01-01

    Two lipid esters of U-14C-labeled and unlabeled gamma-aminobutyric acid (GABA) were synthesized to test the possibility that natural lipid analogues, which resemble normal components of lipid bilayer membranes, can penetrate the blood-brain barrier and transport exogenous GABA to the brain. The uptake of 1-linolenoyl-2,3-bis(4-aminobutyryl)propane-1,2,3-triol and 1,2-dilinolenoyl-3-(4-aminobutyryl)propane-1,2,3-triol into mouse brain relative to liver was found to be, respectively, 75- and 127-fold greater than that of free GABA. The results indicate that there is little or no blood-brain barrier for the GABA ester molecules at doses up to 0.36 mmol/kg. Both ester compounds, but neither free GABA nor the lipid components delivered systemically, demonstrated central nervous system depressant properties by inhibiting the general motor activity of mice. Brain tissue has esterase activity which can release GABA from these compounds. This suggests that these compounds function as "prodrugs" to release GABA in the CNS.

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

    Science.gov (United States)

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

    2016-10-01

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

  7. Photo-Reversible Supramolecular Hydrogels Assembled by α-Cyclodextrin and Azobenzene Substituted Poly(acrylic acid)s

    NARCIS (Netherlands)

    Wang, Mingwei; Zhang, Xiaojun; Li, Li; Wang, Junyou; Wang, Jie; Ma, Jun; Yuan, Zhenyu; Lincoln, Stephen F.; Guo, Xuhong

    2016-01-01

    Photo-reversible supramolecular hydrogels based on the mixture of α-cyclodextrin (α-CD) and azobenzene (Azo) substituted poly(acrylic acid) s were prepared. Effects of substitution degree of Azo, polymer concentration and tethered chain length on the reversible sol-gel transition of these

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

    Science.gov (United States)

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

    2006-02-01

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

  9. Waveguide CP-FTMW and millimeter wave spectra of s-cis- and s-trans-acrylic acid

    Science.gov (United States)

    Alonso, E. R.; Kolesniková, L.; Peña, I.; Shipman, S. T.; Tercero, B.; Cernicharo, J.; Alonso, J. L.

    2015-10-01

    The millimeter wave spectrum of acrylic acid (CH2dbnd CHsbnd COOH), the simplest unsaturated carboxylic acid, was measured and analyzed from 130 to 360 GHz. Additional measurements from 18 to 26.5 GHz were also made using a waveguide CP-FTMW spectrometer. More than 4000 rotational lines were assigned to s-cis- and s-trans-acrylic acid in their ground vibrational states leading to precise determination of rotational, quartic and first complete set of sextic centrifugal distortion constants. New laboratory data of acrylic acid were then used to search for its spectral features in Orion KL, Sgr B2, and W51 molecular clouds. An upper limit to the column density of acrylic acid in Orion KL is provided.

  10. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442) is...

  11. Zeolite-catalysed preparation of alpha-hydroxy carboxylic acids and esters thereof

    DEFF Research Database (Denmark)

    2010-01-01

    A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst.......A process for the production of lactic acid and 2-hydroxy-3-butenoic acid or esters thereof by conversion of glucose, fructose, sucrose, xylose and glycolaldehyde dissolved in a solvent in presence of a solid Lewis acidic catalyst....

  12. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    Science.gov (United States)

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters.

  13. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

    Directory of Open Access Journals (Sweden)

    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  14. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    Science.gov (United States)

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  15. Proteinuria with fumaric acid ester treatment for psoriasis.

    Science.gov (United States)

    Ogilvie, S; Lewis Jones, S; Dawe, R; Foerster, J

    2011-08-01

    Fumaric acid esters (FAE) have been used in the treatment of psoriasis for many years. In general, they are regarded as relatively safe compared with other antipsoriatic systemic treatments, with the most notable adverse effects being gastrointestinal upset, lymphopenia and transient flushing. Renal toxicity has only rarely been reported, and was not found in two independent prospective trials nor in a large retrospective evaluation of almost 1000 patients treated for a median of 44 months. We report three patients developing reversible proteinuria during FAE treatment. One of these displayed the same pattern upon repeated drug administration, thereby clearly indicating FAE treatment to be the causal trigger. The presented cases highlight proteinuria as a clinical concern in FAE treatment. Furthermore, as the novel FAE agent dimethylfumaric (DMF) ester (contained in BG00012/Panaclar) has previously been shown to be effective in psoriasis in a phase III trial and not shown renal toxicity in a large trial for multiple sclerosis, the current report suggests that market introduction of DMF for psoriasis should be pursued. © The Author(s). CED © 2011 British Association of Dermatologists.

  16. Pluronic-poly (acrylic acid)-cysteine/Pluronic L121 mixed micelles improve the oral bioavailability of paclitaxel.

    Science.gov (United States)

    Zhao, Yanli; Li, Yanli; Ge, Jianjun; Li, Na; Li, Ling-Bing

    2014-11-01

    The aim of the study is to synthesize a thiolated Pluronic copolymer, Pluronic-poly (acrylic acid)-cysteine copolymer, to construct a mixed micelle system with the Pluronic-poly (acrylic acid)-cysteine copolymer and Pluronic L121 (PL121) and to evaluate the potential of these mixed micelles as an oral drug delivery system for paclitaxel. Compared with Pluronic-poly (acrylic acid)-cysteine micelles, drug-loading capacity of Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles was increased from 0.4 to 2.87%. In vitro release test indicated that Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles exhibited a pH sensitivity. The permeability of drug-loaded micelles in the intestinal tract was studied with an in situ perfusion method in rats. The presence of verapamil and Pluronic both improved the intestinal permeability of paclitaxel, which further certified the inhibition effect of thiolated Pluronic on P-gp. In pharmacokinetic study, the area under the plasma concentration-time curve (AUC0→∞) of paclitaxel-loaded mixed micelles was four times greater than that of the paclitaxel solution (p acrylic acid)-cysteine/PL121 micelles were proven to be a potential oral drug delivery system for paclitaxel.

  17. Depigmenting Effect of Kojic Acid Esters in Hyperpigmented B16F1 Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Ahmad Firdaus B. Lajis

    2012-01-01

    Full Text Available The depigmenting effect of kojic acid esters synthesized by the esterification of kojic acid using Rhizomucor miehei immobilized lipase was investigated in B16F1 melanoma cells. The depigmenting effect of kojic acid and kojic acid esters was evaluated by the inhibitory effect of melanin formation and tyrosinase activity on alpha-stimulating hormone- (α-MSH- induced melanin synthesis in B16F1 melanoma cells. The cellular tyrosinase inhibitory effect of kojic acid monooleate, kojic acid monolaurate, and kojic acid monopalmitate was found similar to kojic acid at nontoxic doses ranging from 1.95 to 62.5 μg/mL. However, kojic acid monopalmitate gave slightly higher inhibition to melanin formation compared to other inhibitors at doses ranging from 15.63 to 62.5 μg/mL. Kojic acid and kojic acid esters also show antioxidant activity that will enhance the depigmenting effect. The cytotoxicity of kojic acid esters in B16F1 melanoma cells was significantly lower than kojic acid at high doses, ranging from 125 and 500 μg/mL. Since kojic acid esters have lower cytotoxic effect than kojic acid, it is suggested that kojic acid esters can be used as alternatives for a safe skin whitening agent and potential depigmenting agents to treat hyperpigmentation.

  18. Bioequivalence Demonstration for Ω-3 Acid Ethyl Ester Formulations: Rationale for Modification of Current Guidance.

    Science.gov (United States)

    Maki, Kevin C; Johns, Colleen; Harris, William S; Puder, Mark; Freedman, Steven D; Thorsteinsson, Thorsteinn; Daak, Ahmed; Rabinowicz, Adrian L; Sancilio, Frederick D

    2017-03-01

    The US Food and Drug Administration (FDA) draft guidance for establishing bioequivalence (BE) of ω-3 acid ethyl esters (containing both eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA] as ethyl esters), used to treat severe hypertriglyceridemia, recommends the conduct of 2 studies: one with participants in the fasting state and one with participants in the fed state. For the fasting study, the primary measures of BE are baseline-adjusted EPA and DHA levels in total plasma lipids. For the fed study, the primary measures of BE are EPA and DHA ethyl esters in plasma. This guidance differs from that established for icosapent ethyl (EPA ethyl esters) in which the primary measure of BE is baseline-adjusted total EPA in plasma lipids for both the fasting and fed states. The FDA guidance for ω-3 acid ethyl esters is not supported by their physiologic characteristics and triglyceride-lowering mechanisms because EPA and DHA ethyl esters are best characterized as pro-drugs. This article presents an argument for amending the FDA draft guidance for ω-3 acid ethyl esters to use baseline-adjusted EPA and DHA in total plasma lipids as the primary measures of BE for both fasting and fed conditions. This change would harmonize the approaches for demonstration of BE for ω-3 acid ethyl esters and icosapent ethyl (EPA ethyl esters) products for future development programs and is the most physiologically rational approach to BE testing. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

  19. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Science.gov (United States)

    2010-07-01

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

  20. Ferulic acid esters of glucosylglucose from Allium macrostemon Bunge.

    Science.gov (United States)

    Usui, Ayaka; Matsuo, Yosuke; Tanaka, Takashi; Ohshima, Kazusato; Fukuda, Shinji; Mine, Takara; Yakashiro, Ichiro; Ishimaru, Kanji

    2017-03-01

    Three new ferulic acid esters of glucosylglucose, 1-O-(E)-feruloyl-β-d-glucopyranosyl (1-2)-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid A, 1), 1-O-(E)-feruloyl-{β-d-glucopyranosyl (1-4)-[β-d-glucopyranosyl (1-2)]}-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid B, 2), and 1-O-(E)-feruloyl-{β-d-glucopyranosyl (1-6)-[β-d-glucopyranosyl (1-2)]}-[β- d-glucopyranosyl (1-6)]-β-d-glucopyranose (allimacronoid C, 3) were isolated together with tuberonoid A (4), from the leaves of Allium macrostemon Bunge. The chemical structures were elucidated based on the analyses of the spectroscopic and chemical data.

  1. Fumaric acid esters in the management of severe psoriasis.

    Science.gov (United States)

    Brewer, L; Rogers, S

    2007-05-01

    Fumaric acid esters (FAEs) offer an effective alternative to patients with psoriasis in whom other systemic agents are contraindicated or have failed. We assessed the efficacy and side effect profile of FAEs in a group of patients with psoriasis. A retrospective study was carried out on patients treated with FAEs over 21 months. Information was gathered from patients' notes. Dosage, response and side effects were recorded. In total, 31 patients were included. The mean age was 46.8 years. All patients had been treated with other modalities and 61.5% had received previous systemic treatment. There was good to excellent response in 58.6% of patients. Subjective side-effects were common (87.1%), and lymphopenia occurred in 61.3%. The drug was not tolerated by one-fifth of patients. The relatively low toxicity and absence of hepatotoxicity makes FAEs a reasonable first-line systemic treatment in selected patients with difficult psoriasis.

  2. Fumaric acid esters in psoriasis and multiple sclerosis.

    Science.gov (United States)

    Zecca, C; Caporro, M; Adami, M; Mainetti, C; Gobbi, C

    2014-06-01

    Fumaric acid esters (FAEs) are effective in patients with moderate to severe psoriasis. Recent studies also report the efficacy of one FAE component, dimethylfumarate, in relapsing forms of multiple sclerosis (MS). We describe the case of a patient with MS who developed severe plaque psoriasis during interferon-β-1a treatment for MS. The psoriasis was unresponsive to usual topical treatments and phototherapy. The patient was started on FAE 720 mg daily, with complete remission of the psoriatic lesions and neurological stabilization at follow-up at 24 months. Our case suggests that FAEs could represent a therapeutic option for patients with MS who develop plaque psoriasis following exposure to immune-modulating agents. © 2014 British Association of Dermatologists.

  3. Fumaric acid esters in the management of psoriasis

    Directory of Open Access Journals (Sweden)

    Balak DMW

    2015-01-01

    Full Text Available Deepak MW Balak Department of Dermatology, Erasmus Medical Center, Rotterdam, the Netherlands Abstract: Fumaric acid esters (FAE are small molecules with immunomodulating, anti-inflammatory, and anti-oxidative effects. FAE were introduced as a systemic psoriasis treatment in 1959 and empirically developed further between 1970 and 1990 in Germany, Switzerland, and the Netherlands. The development of FAE as psoriasis treatment did not follow the traditional drug development phases. Nonetheless, in 1994 FAE were approved in Germany for the treatment of severe plaque psoriasis. FAE are currently one of the most commonly used treatments in Germany, and FAE are increasingly being used as an unlicensed treatment in several other European countries. To date, six randomized controlled trials and 29 observational studies have evaluated FAE in a combined total of 3,439 patients. The efficacy and safety profile of FAE is favorable. About 50%–70% of patients achieve at least 75% improvement in psoriasis severity after 16 weeks of treatment. Common adverse events of FAE include gastrointestinal complaints and flushing symptoms, which lead to treatment discontinuation in up to 40% of patients. Lymphocytopenia, eosinophilia, and proteinuria are commonly observed during FAE treatment, but rarely require treatment discontinuation. The long-term safety profile of continuous FAE treatment is favorable without an increased risk for infections, malignancies, or other serious adverse events. There are no known drug-interactions for FAE. The 2009 European evidence-based S3-guidelines on psoriasis treatment recommend FAE and suggest it as a first-line systemic treatment for moderate-to-severe plaque psoriasis. This review is aimed to give an overview of FAE treatment in the management of psoriasis. Keywords: fumaric acid esters, fumarates, dimethyl fumarate, Fumaderm, psoriasis, systemic treatment

  4. Synthesis and biological activities of 4-chloroindole-3-acetic acid and its esters.

    Science.gov (United States)

    Katayama, M

    2000-04-01

    4-Chloroindole-3-acetic acid (4-Cl-IAA) and its esters were synthesized from 2-chloro-6-nitrotoluene as the starting material. The biological activities of 4-CI-IAA and its esters were determined by four bioassays. Except for the tert-butyl ester, 4-Cl-IAA and its esters had stronger elongation activity toward Avena coleoptiles than had indole-3-acetic acid. The biological activities of the methyl, ethyl and allyl esters were as strong as the activity of the free acid. All the esters, except for the tert-butyl, inhibited Chinese cabbage hypocotyl growth more than the free acid did, and all the esters induced severe swelling and formation of numerous lateral roots in black gram seedlings even at a low concentration. Furthermore, adventitious root formation was strongly promoted in Serissa japonica cuttings by all the esters. The root formation-promoting activities of the ethyl and allyl esters were about three times the value for indole-3-butyric acid which is used to promote and accelerate root formation in plant cuttings.

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

    Science.gov (United States)

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

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

  6. Effect of variations in the fatty acid chain on functional properties of oligofructose fatty acid esters

    NARCIS (Netherlands)

    Kempen, van S.E.H.J.; Schols, H.A.; Linden, van der E.; Sagis, L.M.C.

    2014-01-01

    Oligofructose fatty acid esters are surfactants that considerably lower the surface tension of an air/water interface, provide the interface with a high dilatational modulus and lead to a high foam stability. In this study, we investigate the effect of the molecular structure of oligofructose fatty

  7. Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

    Science.gov (United States)

    Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

    2012-11-01

    The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

    Weber, Arthur L.; Hsu, Victor

    1990-01-01

    The apparent Gibbs free energy change (GFEC) of hydrolysis (pH 7) of the 2- and 3-O-glyceroyl esters of 2- and 3-O-L-glyceroyl-L-glyceric acid methyl ester were measured at 25 C. The 2- and 3-glyceroyl esters were found to be 'energy-rich' with GFEC values of -9.1 kcal/mol and -7.8 kcal/mol, respectively. This result indicates that the analogous 2- and 3-glyceroyl esters of polyglyceric acid are also energy-rich and, therefore, could have acted as an energy source for primitive phosphoanhydride synthesis.

  9. A New 31P NMR Method for the Enantiomeric Excess Determination of Alcohols, Amines and Amino Acid Esters.

    NARCIS (Netherlands)

    Hulst, Ron; Zijlstra, Robert W.J.; Vries, N. Koen de; Hoeve, Wolter ten; Wynberg, Hans; Feringa, Bernard

    1993-01-01

    Diastereoisomeric ester and amide derivatives of phosphoric acid chloride 2 show well separated signals in the 31P NMR spectra allowing accurate e.e. determination of chiral alcohols, esters of amino acids and amines.

  10. A NEW P-31 NMR METHOD FOR THE ENANTIOMERIC EXCESS DETERMINATION OF ALCOHOLS, AMINES AND AMINO-ACID ESTERS

    NARCIS (Netherlands)

    HULST, R; ZIJLSTRA, RWJ; FERINGA, BL; DEVRIES, NK; TENHOEVE, W; WYNBERG, H

    1993-01-01

    Diastereoisomeric ester and amide derivatives of phosphoric acid chloride 2 show well separated signals in the P-31 NMR spectra allowing accurate e.e. determination of chiral alcohols, esters of amino acids and amines.

  11. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs); Sintese de novas amidas graxas a partir da aminolise de esteres metilicos

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carolina R.; Montes D' Oca, Caroline da Ros; Duarte, Rodrigo da C.; Kurz, Marcia H.S.; Primel, Ednei G.; Clementin, Rosilene M.; Villarreyes, Joaquin Ariel M.; Montes D' Oca, Marcelo G., E-mail: dqmdoca@furg.b [Universidade Federal do Rio Grande, RS (Brazil). Escola de Quimica e Alimentos

    2010-07-01

    Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

  12. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid-chitosan

    Directory of Open Access Journals (Sweden)

    Hortensia Ortega-Ortiz

    2010-06-01

    Full Text Available The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid.A atividade antimicrobiana de quitosana e complexos interpolieletrolíticos hidrossoluvéis de poli(ácido acrílico-quitosana foi estudada. Quitosanas de dois diferentes pesos moleculares foram testados em diferentes concentrações, 0,5 a 5 g • L-1, como agentes antimicrobianos nas P. aeruginosa e P. oleovorans. Em ambos os casos, obteu-se a melhor inibição microbiana com a concentração de 5 g • L-1, no entanto os complexos interpolieletrolíticos de poli (ácido acrílico-quitosana com composição φ = 2 apresentaram maior atividade antibacteriana do que os dois quitosans na concentração de 0,5 g • L-1. O complexo NPEC2 foi mais eficaz do que as quitosanas, sendo que o resultado pode ser atribuído ao número de moles dos grupos aminos da quitosana e aos grupos carboxílicos dos complexos de poli(ácido acrílico.

  13. Predicting the Viscosity of Low VOC Vinyl Ester and Fatty Acid-Based Resins

    Science.gov (United States)

    2005-12-01

    1) (1). Epon 828 , 834, 836, 1001F, 1004F, 1007F, and 1009F (Miller- Stephenson, Danbury, CT) were used as the source of DGEBA. To determine the...Figure 1. The reaction of methacrylic acid with Epon to form vinyl-ester monomer. Pure vinyl ester was prepared via methacrylation of Epon 828 ...resins prepared. Bimodal blends of vinyl-ester monomers (BM-VE) were prepared by methacrylation of blends of Epon 828 , used as the low molecular weight

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

    OpenAIRE

    Ramesh Ramapanicker; Rohit Gupta; Rajendran Megha; Srinivasan Chandrasekaran

    2011-01-01

    Propargyl esters are employed as effective protecting groups for the carboxyl group during solution-phase peptide synthesis. The propargyl ester groups can be introduced onto free amino acids by treating them with propargyl alcohol saturated with HCl. The reaction between propargyl groups and tetrathiomolybdate is exploited to deblock the propargyl esters. The removal of the propargyl group with the neutral reagent tetrathiomolybdate ensures that most of the other protecting groups used in pe...

  15. 40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetic acid, , 1-methyl hexyl ester... Substances § 721.304 Acetic acid, , 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as acetic acid, -, 1-methylhexyl ester (PMN P...

  16. 75 FR 20785 - Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the Requirement of a...

    Science.gov (United States)

    2010-04-21

    ... AGENCY 40 CFR Part 180 Polyglyceryl Phthalate Ester of Coconut Oil Fatty Acids; Exemption from the..., concerning polyglyceryl phthalate ester of coconut oil fatty acids; exemption from the requirement of a... phthalate ester of coconut oil fatty acids'' pursuant to a petition by the Joint Inserts Task Force, Cluster...

  17. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  18. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

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

    Science.gov (United States)

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

    2011-01-01

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

  20. Applications of propargyl esters of amino acids in solution-phase Peptide synthesis.

    Science.gov (United States)

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ramesh Ramapanicker

    2011-01-01

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

  2. Depletion of abundant plasma proteins by poly(N-isopropylacrylamide-acrylic acid) hydrogel particles

    DEFF Research Database (Denmark)

    Such-Sanmartín, Gerard; Ventura-Espejo, Estela; Jensen, Ole N

    2014-01-01

    the application of pH-sensitive poly(N-isopropylacrylamide-acrylic acid) hydrogel particles for removal of abundant plasma proteins, prior to proteome analysis by MS. Protein depletion occurs by two separate mechanisms: (1) hydrogel particles incubated with low concentrations of plasma capture abundant proteins...... at higher efficiency than low abundance proteins, which are enriched in the supernatants, whereas (2) hydrogel particles incubated with high concentrations of plasma capture and irreversibly trap abundant proteins. During the elution step, irreversibly trapped proteins remain captured while low abundance...... (SRM) liquid chromatography (LC)-MS/MS. This novel use of hydrogel particles opens new perspectives for biomarker analysis based on mass spectrometry....

  3. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter

    2005-01-01

    is investigated by titration, differential scanning calorimetry (DSC) and capillary rheometry. The titration experiments indicates that the polymerization is a block copolymerization and the DSC result show that the blocks of poly(N-isopropylacrylamide) are not randomly distributed in the microgels. Capillary...... concentrations of acrylic acid as co-monomer. The microgels have a charge density between 0.2 and 0.9 mmol/g.   Preliminary filtration experiments show that filtration properties of the microgel model system significantly differs from the properties for inorganic colloidals such as titaniumdioxid....

  4. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Science.gov (United States)

    2010-04-01

    ... propylene glycol. 172.850 Section 172.850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... esters of glycerol and propylene glycol. The food additive lactylated fatty acid esters of glycerol and propylene glycol may be safely used in food in accordance with the following prescribed conditions: (a) The...

  5. Acrylic-acid-functionalized PolyHIPE scaffolds for use in 3D cell culture.

    Science.gov (United States)

    Hayward, Adam S; Sano, Naoko; Przyborski, Stefan A; Cameron, Neil R

    2013-12-01

    This study describes the development of a functional porous polymer for use as a scaffold to support 3D hepatocyte culture. A high internal phase emulsion (HIPE) is prepared containing the monomers styrene (STY), divinylbenzene (DVB), and 2-ethylhexyl acrylate (EHA) in the external oil phase and the monomer acrylic acid (Aa) in the internal aqueous phase. Upon thermal polymerization with azobisisobutyronitrile (AIBN), the resulting porous polymer (polyHIPE) is found to have an open-cell morphology and a porosity of 89%, both suitable characteristics for 3D cell scaffold applications. X-ray photo-electron spectroscopy reveals that the polyHIPE surface contained 7.5% carboxylic acid functionality, providing a useful substrate for subsequent surface modifications and bio-conjugations. Initial bio-compatibility assessments with human hepatocytes show that the acid functionality does not have any detrimental effect on cell adhesion. It is therefore believed that this material can be a useful precursor scaffold towards 3D substrates that offer tailored surface functionality for enhanced cell adhesion. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Science.gov (United States)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  7. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  8. Enzymatic synthesis of arbutin undecylenic acid ester and its inhibitory effect on melanin synthesis.

    Science.gov (United States)

    Tokiwa, Yutaka; Kitagawa, Masaru; Raku, Takao; Yanagitani, Shusaku; Yoshino, Kenji

    2007-06-01

    Transesterification of arbutin and undecylenic acid vinyl ester was catalyzed by alkaline protease, Bioprase, in dimethylformamide to get arbutin derivative having undecylenic acid at 6-position of glucose moiety, 6-O-undecylenoyl p-hydroxyphenyl beta-D-glucopyranoside. The reaction rate increased with increase of arbutin concentration, and when its concentration was 0.9 M, the conversion rate was more than 90% under addition of 2 M undecylenic acid vinyl ester. The obtained arbutin ester significantly suppressed melanin production in murine B16 melanoma cells.

  9. Sugar fatty acid esters inhibit biofilm formation by food-borne pathogenic bacteria

    Science.gov (United States)

    Furukawa, Soichi; Akiyoshi, Yuko; O’Toole, George A.; Ogihara, Hirokazu; Morinaga, Yasushi

    2010-01-01

    Effects of food additives on biofilm formation by food-borne pathogenic bacteria were investigated. Thirty-three potential food additives and 3 related compounds were added to the culture medium at concentrations from 0.001 to 0.1% (w/w), followed by inoculation and cultivation of five biofilm-forming bacterial strains for the evaluation of biofilm formation. Among the tested food additives, 21 showed inhibitory effects of biofilm formation by Staphylococcus aureus and Escherichia coli, and in particular, sugar fatty acid esters showed significant anti-biofilm activity. Sugar fatty acid esters with long chain fatty acid residues (C14-16) exerted their inhibitory effect at the concentration of 0.001%(w/w), but bacterial growth was not affected at this low concentration. Activities of the sugar fatty acid esters positively correlated with the increase of the chain length of the fatty acid residues. Sugar fatty acid esters inhibited the initial attachment of the Staphylococcus aureus cells to the abiotic surface. Sugar fatty acid esters with long chain fatty acid residues (C14-16) also inhibited biofilm formation by Streptococcus mutans and Listeria monocytogenes at 0.01%(w/w), while the inhibition of biofilm formation by Pseudomonas aeruginosa required the addition of a far higher concentration (0.1%(w/w)) of the sugar fatty acid esters. PMID:20089325

  10. Chemometric analysis of mass spectra of cis and trans fatty acid picolinyl esters

    DEFF Research Database (Denmark)

    Leth, Torben

    1997-01-01

    Capillary GC of fatty acid methyl esters with MS detection only yields information about the molecular weight of the compound. However, if picolinyl esters of fatty acids are analysed in this way it is possible to obtain more information about their structure, perhaps even the cis or trans...... with a quadropole MS-detector. The mass spectra clearly show the molecular weight and the position of double bonds in the fatty acids, but whether the configuration is cis or trans is impossible to discern visually. However, with the use of principal component analysis, it is possible to distinguish between cis...... configuration. Picolinyl esters of fatty acids are prepared by adding carbonyl-diimidazole, 3-hydroxy-methylpyridine and 4-pyrrolidin-o-pyridine to a solution of free fatty acids in dichloromethane. The picolinyl esters dissolved in heptane are then separated by capillary GC on a CP Sil 88 column equipped...

  11. Successful treatment of recalcitrant cutaneous sarcoidosis with fumaric acid esters

    Directory of Open Access Journals (Sweden)

    Hanefeld Christoph

    2002-12-01

    Full Text Available Abstract Background Sarcoidosis is a multisystem disease of unknown origin characterized by the formation of noncaseating granulomas, in particular in the lungs, lymph nodes, eyes, and skin. Systemic treatment for cutaneous sarcoidosis can be used for large disfiguring lesions, generalized involvement, or recalcitrant lesions that did not respond to topical therapy. Case presentations We report three patients with recalcitrant cutaneous sarcoidosis who were treated with oral fumaric acid esters (FAE. Three female patients presented with cutaneous sarcoidosis that have proved to be refractory to various therapies, including corticosteroids and chloroquine. We treated the patients with FAE in tablet form using two formulations differing in strength (Fumaderm® initial, Fumaderm®. Dosage of FAE was performed according to the standard therapy regimen for psoriasis patients. After treatment with FAE (4–12 months, a complete clearance of skin lesions was achieved in the three patients. The side effects observed in this trial correspond to the well-known spectrum of adverse effects of FAE (flush, minor gastrointestinal complaints, lymphopenia. Conclusions On the basis of our findings FAE therapy seems to be a safe and effective regimen for patients with recalcitrant cutaneous sarcoidosis. Nevertheless further investigations are necessary to confirm our preliminary results.

  12. Successful treatment of recalcitrant cutaneous sarcoidosis with fumaric acid esters

    Science.gov (United States)

    Nowack, Ute; Gambichler, Thilo; Hanefeld, Christoph; Kastner, Ulrike; Altmeyer, Peter

    2002-01-01

    Background Sarcoidosis is a multisystem disease of unknown origin characterized by the formation of noncaseating granulomas, in particular in the lungs, lymph nodes, eyes, and skin. Systemic treatment for cutaneous sarcoidosis can be used for large disfiguring lesions, generalized involvement, or recalcitrant lesions that did not respond to topical therapy. Case presentations We report three patients with recalcitrant cutaneous sarcoidosis who were treated with oral fumaric acid esters (FAE). Three female patients presented with cutaneous sarcoidosis that have proved to be refractory to various therapies, including corticosteroids and chloroquine. We treated the patients with FAE in tablet form using two formulations differing in strength (Fumaderm® initial, Fumaderm®). Dosage of FAE was performed according to the standard therapy regimen for psoriasis patients. After treatment with FAE (4–12 months), a complete clearance of skin lesions was achieved in the three patients. The side effects observed in this trial correspond to the well-known spectrum of adverse effects of FAE (flush, minor gastrointestinal complaints, lymphopenia). Conclusions On the basis of our findings FAE therapy seems to be a safe and effective regimen for patients with recalcitrant cutaneous sarcoidosis. Nevertheless further investigations are necessary to confirm our preliminary results. PMID:12498617

  13. Preparation and characterization of polyacrylamide-modified kaolinite containing poly [acrylic acid-co-methylene bisacrylamide] nanocomposite hydrogels

    DEFF Research Database (Denmark)

    Zaharia, Anamaria; Sarbu, Andrei; Radu, Anita-Laura

    2015-01-01

    Novel nanocomposite hydrogel structures based on cross-linked poly(acrylic acid) (PAA) and kaolinite (Kaol), modified with different loadings of polyacrylamide (PAAm), were prepared by inverse dispersion polymerization. Ceric ammonium nitrate as an initiator in the presence of nitric acid was used...

  14. Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2004-05-24

    Full Text Available The coupling reaction between ethyl acetoacetate and a number of aryl halides in the presence of palladium acetate, a bulky and electron rich phosphine and K3PO4 is described. The arylated acetoacetate ester is de-acylated under the reaction...

  15. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Luo, Shi-Zhong [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Wang, Bin, E-mail: bin_wang@scu.edu.cn [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Guo, ZhanHu [Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-08-01

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (M{sub W} 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  16. Poly(acrylic acid) modifying bentonite with in-situ polymerization for removing lead ions.

    Science.gov (United States)

    He, Y F; Zhang, L; Yan, D Z; Liu, S L; Wang, H; Li, H R; Wang, R M

    2012-01-01

    In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5-60 min), initial concentration of metal ions (200-1,000 mg/L) and adsorbent dosage (0.04-0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).

  17. Controlled release of anti-diabetic drug Gliclazide from poly(caprolactone)/poly(acrylic acid) hydrogels.

    Science.gov (United States)

    Bajpai, S K; Chand, Navin; Soni, Shweta

    2015-01-01

    Drug Gliclazide (Glz) has limited solubility and low bioavailability. In order to obtain a controlled release of this drug and to improve its bioavailability, the drug has been loaded into poly(caprolactone) (PCL)/poly(acrylic acid) (PAAc) hydrogels, prepared by free radical polymerization of acrylic acid in the presence of poly(caprolactone) in acetone medium using azo-isobutyronitrile as initiator and N,N' methylene bisacrylamide as cross-linking agent. The swelling behaviour of these hydrogels has been investigated in the physiological gastric and intestinal fluids to obtain an optimum composition suitable for delivery of a biologically active compound. The gels were loaded with anti-diabetic drug Glz and a detailed investigation of release of drug has been carried out. Various kinetic models have been applied on the release data. Finally, the Albino wistar rats were treated for Streptozotocin plus nicotinamide - induced diabetes using a Glz-loaded PCL/PAAc hydrogel. The results indicated a fair reduction in the glucose level of rats.

  18. Acrylic Acid Improved Nylon 66 Fabric by Electron Beam Irradiation-induced Grafting

    Directory of Open Access Journals (Sweden)

    SANG Wei

    2017-10-01

    Full Text Available Acrylic acid was grafted onto nylon 66 fabric by the electron beam irradiation method. Effects of different grafting conditions on grafting reaction were investigated. Fourier transform infrared spectroscopy(FTIR, thermo gravimetric analyzer(TGA, scanning electron microscope(SEM and YG065 type fabric strength tester were used to characterize the chemical structures, thermal properties, surface morphology and mechanical properties of these prepared nylon 66 fabric samples. And the anti-dripping performance was evaluated by the vertical burning. The results show that in FTIR spectrum new absorption peeks at 1720.2 cm-1 and other wave numbers are assigned to the carboxyl groups, which imply that acrylic acid is successfully grafted to the nylon 66 molecular. The anti-dripping performance of nylon 66 fabric is improved significantly after grafting. It can be attributed to the cross-linked char layer which subsequently provides a support for the melting fiber. However, the mechanical properties of grafted samples decrease to some extent. With the increase of grafting ratio, the onset temperatures of grafted samples decrease gradually, while the char-forming performance enhances significantly. Besides, the damage length and droplet velocity of grafted samples become shorter and lower, and the tensile strength at break increases slightly.

  19. Accurate determination of residual acrylic acid in superabsorbent polymer of hygiene products by headspace gas chromatography.

    Science.gov (United States)

    Zhang, Shu-Xin; Chai, Xin-Sheng; Jiang, Ran

    2017-02-17

    This work reports on a method for the determination of residual acrylic acid (AA) in the superabsorbent polymers for hygiene products by headspace analysis. It was based on water extraction for the polymer sample at a room temperature for 50min. Then, the AA in the extractant reacted with bicarbonate solution in a closed headspace sample vial, from which the carbon dioxide generated from the reaction (within 20min at 70°C) was detected by gas chromatography (GC). It was found that there is adsorption partition equilibrium of AA between solid-liquid phases. Therefore, an equation for calculating the total AA content in the original polymers sample was derived based on the above phase equilibrium. The results show that the HS-GC method has good precision (RSD<2.51%) and good accuracy (recoveries from 93 to 105%); the limit of quantification (LOQ) was 373mg/kg. The present method is rapid, accurate, and suitable for determining total residual acrylic acid in a wide variety of applications from processing of superabsorbent polymer to commercial products quality control. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Potassium fulvate-modified graft copolymer of acrylic acid onto cellulose as efficient chelating polymeric sorbent.

    Science.gov (United States)

    Mohamed, Magdy F; Essawy, Hisham A; Ammar, Nabila S; Ibrahim, Hanan S

    2017-01-01

    Acrylic acid (AA) was graft copolymerized from cellulose (Cell) in presence of potassium fulvate (KF) in order to enhance the chemical activity of the resulting chelating polymer and the handling as well. Fourier transform infrared (FTIR) proved that KF was efficiently inserted and became a permanent part of the network structure of the sorbent in parallel during the grafting copolymerization. Scanning electron microscopy (SEM) revealed intact homogeneous structure with uniform surface. This indicates improvement of the handling, however, it was not the case for the graft copolymer of acrylic acid onto cellulose in absence of KF, which is known to be brittle and lacks mechanical integrity. Effective insertion of this co-interpenetrating agent provided more functional groups, such as OH and COOH, which improved the chelating power of the produced sorbent as found for the removal of Cu(2+) ions from its aqueous solutions (the removal efficiency reached ∼98.9%). Different models were used to express the experimental data. The results corroborated conformity of the pseudo-second order kinetic model and Langmuir isotherm model to the sorption process, which translates into dominance of the chemisorption. Regeneration of the chelating polymers under harsh conditions did not affect the efficiency of copper ions uptake up to three successive cycles. A thermodynamic investigation ensured exothermic nature of the adsorption process that became less favourable at higher temperatures. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Superhydrophobic surface fabricated by bulk photografting of acrylic acid onto high-density polyethylene.

    Science.gov (United States)

    Han, Jianmei; Wang, Xiaoxiao; Wang, Huiliang

    2008-10-15

    A superhydrophobic polymeric surface was prepared through a very simple bulk photografting method. A thin layer of acrylic acid (AA), a highly hydrophilic monomer, was sandwiched between two high-density polyethylene (HDPE) sheets, followed by UV irradiation for a short time, and then the two sheets were pulled apart and dried. The contact angles on the two grafted surfaces decreased very quickly with irradiation time in the first several seconds, and then increased with irradiation time to a level higher than that on pristine HDPE surface. When using a scraped PE surface as the bottom one, it showed superhydrophobicity after 35 s irradiation. XPS investigations show that strong rearrangement of the poly(acrylic acid) molecules has taken place on both surfaces, especially on the bottom surface, which provides the low surface free energy. The scraping and the grafting process led to the formation a unique micro- and nanostructure on the surface. These two factors lead to the superhydrophobicity. The as-prepared surface possesses superhydrophobic properties in a wide range of pH values, stimuli-responsive properties and low or very high adhesion under different situations.

  2. Preparation of Caco-2 cell sheets using plasma polymerised acrylic acid as a weak boundary layer.

    Science.gov (United States)

    Majani, Ruby; Zelzer, Mischa; Gadegaard, Nikolaj; Rose, Felicity R; Alexander, Morgan R

    2010-09-01

    The use of cell sheets for tissue engineering applications has considerable advantages over single cell seeding techniques. So far, only thermoresponsive surfaces have been used to manufacture cell sheets without chemically disrupting the cell-surface interactions. Here, we present a new and facile technique to prepare sheets of epithelial cells using plasma polymerised acrylic acid films. The cell sheets are harvested by gentle agitation of the media without the need of any additional external stimulus. We demonstrate that the plasma polymer deposition conditions affect the viability and metabolic activity of the cells in the sheet and relate these effects to the different surface properties of the plasma polymerised acrylic acid films. Based on surface analysis data, a first attempt is made to explain the mechanism behind the cell sheet formation. The advantage of the epithelial cell sheets generated here over single cell suspensions to seed a PLGA scaffold is presented. The scaffold itself, prepared using a mould fabricated via photolithography, exhibits a unique architecture that mimics closely the dimensions of the native tissue (mouse intestine). Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Polyurethane modification with acrylic acid by Ce(IV-initiated graft polymerization

    Directory of Open Access Journals (Sweden)

    Butruk-Raszeja Beata A.

    2016-01-01

    Full Text Available This paper presents a method for polyurethane surface functionalization for tissue engineering applications. Functionalization has been carried out by grafting acrylic acid to the polyurethane surface with the use of radical polymerization with a Ce4+ initiator. Contrary to other papers suggesting that the presence of hydroxyl groups are essential for successful grafting via ceric ions, we propose a method with the omission of the surface hydroxylation step. The influence of reaction conditions: reaction time, reaction temperature and monomer concentration on carboxyl groups surface density has been analyzed and described. The quantity of carboxyl groups on the surface was determined with the use of the TBO method. Materials grafted with acrylic acid have been subjected to conjugation with a peptide using sulfoNHS/ EDC chemistry. Successful incorporation of the peptide has been confirmed by an ELISA assay. Additionally, for better characterization, after each step of modification materials were subjected to SEM, FTIR-ATR, XPS and contact angle measurement analysis.

  4. Gallium-modified chitosan/poly(acrylic acid) bilayer coatings for improved titanium implant performances.

    Science.gov (United States)

    Bonifacio, Maria A; Cometa, Stefania; Dicarlo, Manuela; Baruzzi, Federico; de Candia, Silvia; Gloria, Antonio; Giangregorio, Maria M; Mattioli-Belmonte, Monica; De Giglio, Elvira

    2017-06-15

    A gallium-modified chitosan/poly(acrylic acid) bilayer was obtained by electrochemical techniques on titanium to reduce orthopaedic and/or dental implants failure. The bilayer in vitro antibacterial properties and biocompatibility were evaluated against Escherichia coli and Pseudomonas aeruginosa and on MG63 osteoblast-like cells, respectively. Gallium loading into the bilayer was carefully tuned by the electrochemical deposition time to ensure the best balance between antibacterial activity and cytocompatibility. The 30min deposition time was able to reduce in vitro the viable cell counts of E. coli and P. aeruginosa of 2 and 3 log cfu/sheet, respectively. Our results evidenced that the developed antibacterial coating did not considerably alter the mechanical flexural properties of titanium substrates and, in addition, influenced positively MG63 adhesion and proliferation. Therefore, the gallium-modified chitosan/poly(acrylic acid) bilayer can be exploited as a promising titanium coating to limit bacterial adhesion and proliferation, while maintaining osseointegrative potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. CHARACTERISTIC OF ACRYLIC ACID GRAFTED POLYETHYLENE FILM PREPARED BY GAMMA IRRADIATION METHOD

    Directory of Open Access Journals (Sweden)

    John Hendri

    2010-06-01

    Full Text Available In this study, high density polyethylene (PE film (thickness 80 μm was modified by grafting of acrylic acid (AA onto the film using 15 kGy of g irradiation as initiator, applied at different exposure times. In addition to irradiation dose, other variables investigated are concentration of AA, the type of solvent, and polymerization time carried out at 60 oC. The success of the graft copolymerization processes was confirmed by analysing the grafted film using FTIR spectroscopy, which revealed the existence of absorption band at wave number of 1721 cm-1 (assigned to C=O, and that at 3385 cm-1 (assigned to -OH, and the physical endurance of the sample was evaluated by carrying out tensile strength measurement. The percent of grafting was determined according to the gravimetric method. The results indicated that the highest percent of grafting was obtained by application of 2-hour irradiation time, with monomer concentration of 30 % in water as a solvent, grafting temperature of 60 oC. Activity of grafted was evaluated by measurement of the absorption capacity toward water and Cu2+ ion, and revealed the increase of the absorption capacity with increased percent of grafting.   Keywords: Graft copolymerization, acrylic acid, low density polyethylene, gamma irradiation, water absorbency, absorption of cupric ion

  6. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Science.gov (United States)

    2010-04-01

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

  7. A Convenient Synthesis and Antibacterial Activity of Novel α-Aminophosphonic Acid Esters from Amino Acids/Esters (Kabachnik-Fields Reaction

    Directory of Open Access Journals (Sweden)

    CH. Mohan

    2008-01-01

    Full Text Available Synthesis of novel α-aminophosphonic acid esters (5a-n were achieved with high yields through one-pot three component reaction process by Kabachnik-Fields reaction. It involves the reaction among amino acids/esters, substituted aromatic aldehydes and dialkyl phosphites in absolute ethanol at reflux temperature. Their structures were established by elemental analysis IR, ¹H, ¹³C, ³¹P NMR and mass spectral data. All the title compounds were screened for their antibacterial activity. Most of the compounds exhibited moderate antimicrobial activity.

  8. Synthesis of fatty acid sterol esters using cholesterol esterase from Trichoderma sp. AS59.

    Science.gov (United States)

    Morinaga, Naoya; Maeda, Atsushi; Mizuno, Takayuki; Bunya, Masanori; Sugihara, Shigeo; Sugihara, Akio

    2011-05-06

    We recently reported the characterization of novel cholesterol esterase (EC. 3.1.1.13) from Trichoderma sp. and preliminary work on sterol ester synthesis. In the present study, we further examined the enzyme ability to synthesize cholesterol esters from cholesterol and free fatty acids of various chain lengths, and compared the fatty acid specificity in synthesis with that in hydrolysis. The enzyme catalyzed the synthesis of medium- and long-chain fatty acid cholesterol esters, but failed to synthesize short-chain fatty acid esters. The fatty acid specificities in the synthesis and hydrolysis of cholesterol esters were entirely different from each other. Unlike other lipolytic enzymes, the enzyme was largely independent of water content in the synthesis of cholesterol oleate, and it achieved near-complete esterification in the presence of an equimolar excess of oleic acid. Of additional interest is the finding that the addition of n-hexane markedly enhanced the esterification activities on all the medium- and long-chain saturated fatty acids used. Based on these findings, we attempted to synthesize stigmasterol stearate as a food additive to lower cholesterol levels in blood plasma, and found that the enzyme catalyzed effective synthesis of the ester without the need of dehydration during the reaction, indicating the potential utility of the enzyme in the food industry. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Oxidative stability of fatty acid alkyl esters: a review.

    Directory of Open Access Journals (Sweden)

    Michal Angelovič

    2015-12-01

    Full Text Available The purpose of this study was to investigate and to process the current literary knowledge of the physico-chemical properties of vegetable oil raw used for biodiesel production in terms of its qualitative stability. An object of investigation was oxidative stability of biodiesel. In the study, we focused on the qualitative physico-chemical properties of vegetable oils used for biodiesel production, oxidative degradation and its mechanisms, oxidation of lipids, mechanisms of autooxidation, effectivennes of different synthetic antioxidants in relation to oxidative stability of biodiesel and methods of oxidative stability determination. Knowledge of the physical and chemical properties of vegetable oil as raw material and the factors affecting these properties is critical for the production of quality biodiesel and its sustainability. According to the source of oilseed, variations in the chemical composition of the vegetable oil are expressed by variations in the molar ratio among different fatty acids in the structure. The relative ratio of fatty acids present in the raw material is kept relatively constant after the transesterification reaction. The quality of biodiesel physico-chemical properties is influenced by the chain length and the level of unsaturation of the produced fatty acid alkyl esters. A biodiesel is thermodynamically stable. Its instability primarily occurs from contact of oxygen present in the ambient air that is referred to as oxidative instability. For biodiesel is oxidation stability a general term. It is necessary to distinguish ‘storage stability' and ‘thermal stability', in relation to oxidative degradation, which may occur during extended periods of storage, transportation and end use. Fuel instability problems can be of two related types, short-term oxidative instability and long-term storage instability. Storage instability is defined in terms of solid formation, which can plug nozzles, filters, and degrade engine

  10. 21 CFR 178.3780 - Polyhydric alcohol esters of long chain monobasic acids.

    Science.gov (United States)

    2010-04-01

    ... monobasic acids consist of polyhydric alcohol esters having number average molecular weights in the range of.../code_of_federal_regulations/ibr_locations.html. (4) Ultraviolet absorbance as specified in § 178.3770(a...

  11. Simple and Convenient Synthesis of Esters from Carboxylic Acids and Alkyl Halides Using Tetrabutylammonium Fluoride

    National Research Council Canada - National Science Library

    Matsumoto, Kouichi; Shimazaki, Hayato; Miyamoto, Yu; Shimada, Kazuaki; Haga, Fumi; Yamada, Yuki; Miyazawa, Hirotsugu; Nishiwaki, Keiji; Kashimura, Shigenori

    2014-01-01

    A simple and convenient method has been developed for the synthesis of esters from the corresponding carboxylic acids and alkyl halides by using a stoichiometric amount of tetrabutylammonium fluoride (Bu4NF) as the base...

  12. Enzymatic Synthesis of Hydroxycinnamic Acid Glycerol Esters Using Type A Feruloyl Esterase from Aspergillus niger

    National Research Council Canada - National Science Library

    TSUCHIYAMA, Moriyasu; SAKAMOTO, Tatsuji; TANIMORI, Shinji; MURATA, Shuichi; KAWASAKI, Haruhiko

    2007-01-01

    We found that hydroxycinnamic acid (HA) glycerol esters such as 1-sinapoyl glycerol and 1-p-coumaroyl glycerol can be synthesized through a direct esterification reaction using a type A feruloyl esterase from Aspergillus niger...

  13. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: A case series

    National Research Council Canada - National Science Library

    Balak, Deepak; Bavinck, Jan Nico Bouwes; De Vries, A.P.J; Hartman, J; Martino Neumann, H.A; Zietse, Bob; Thio, Bing

    2016-01-01

    textabstractBackground: Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome...

  14. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    OpenAIRE

    Liangming Wei; Changxin Chen; Zhongyu Hou; Hao Wei

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dim...

  15. Enhancement of Emulsifying Properties of Cuttlefish Skin Gelatin by Modification with N-hydroxysuccinimide Esters of Fatty Acids

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Encarnacion, A.B.; Wierenga, P.A.; Gruppen, H.

    2013-01-01

    Cuttlefish (Sepia pharaonis) skin gelatin modified with N-hydroxysuccinimide esters of various fatty acids including capric acid (C10:0), lauric acid (C12:0), and myristic acid (C14:0) at different molar ratios was characterized and determined for emulsifying property. Fatty acid esters were

  16. Engineering Escherichia coli with acrylate pathway genes for propionic acid synthesis and its impact on mixed-acid fermentation.

    Science.gov (United States)

    Kandasamy, Vijayalakshmi; Vaidyanathan, Hema; Djurdjevic, Ivana; Jayamani, Elamparithi; Ramachandran, K B; Buckel, Wolfgang; Jayaraman, Guhan; Ramalingam, Subramanian

    2013-02-01

    Fermentation-derived products are in greater demand to meet the increasing global market as well as to overcome environmental problems. In this work, Escherichia coli has been metabolically engineered with acrylate pathway genes from Clostridium propionicum for the conversion of D-lactic acid to propionic acid. The introduced synthetic pathway consisted of seven genes encoding the enzymes propionate CoA-transferase (Pct), lactoyl-CoA dehydratase (Lcd) and acryloyl-CoA reductase (Acr). The engineered strain synthesised propionic acid at a concentration of 3.7 ± 0.2 mM upon fermentation on glucose. This low production level could be attributed to the low activity of the recombinant enzymes in particular the rate-limiting enzyme, Acr. Interestingly, the recombinant pathway caused an increased lactate production in E. coli with a yield of 1.9 mol/mol of glucose consumed along with a decrease in other by-products. Down-regulation of the pfl (pyruvate formate lyase) genes and a possible inhibition of Pfl activity by the acrylate pathway intermediate, acryloyl-CoA, could have reduced carbon flow to the Pfl pathway with a concomitant increase in lactate production. This study reports a novel way of synthesising propionic acid by employing a non-native, user-friendly organism through metabolic engineering.

  17. Immunogenicity of aryl esters of salicylic or acetylsalicylic acid in guinea pigs.

    Science.gov (United States)

    Schlumberger, H D

    1975-01-01

    A variety of derivatives of acetylsalicylic and salicylic acid have been investigated for their immunogenic properties in guinea pigs including salicylsalicylic acid (SSA), acetylsalicylsalicylic acid (ASSA), disalicylide (DI), trisalicylide (TRI), acetylsalicylic acid paracetamol ester (ASPE) and acetylsalicylic acid guajacol ester (ASGE). Contact sensitivity could be elicited by the sensitizing agent, however, with acetylsalicylic acid anhydride (ASAN) a more pronounced contact reaction could consistently be observed. Systemic anaphylactic reactions elicited by intravenous injection of N-salicyloyl bovine serum albumin could only be induced by ASAN, DI, TRI and ASSA, whereas SSA, ASPE and ASGE did not induce an anaphylactic state at a comparable dose level. From these results it is anticipated that all aryl esters of acetylsalicylic or salicylic acid are immunogenic when applied intradermally, leading to a N-salicyloyl specific immune response.

  18. Fumaric acid esters for psoriasis: a systematic review.

    Science.gov (United States)

    Smith, D

    2017-02-01

    Psoriasis is a chronic skin disease associated with increased morbidity and mortality. Effective and safe long term treatment options are required to manage the illness successfully. A number of systemic agents are available, however, each of them has potentially significant side effects. Fumaric acid esters (FAE) are used first line in Germany for the management of moderate to severe psoriasis, however, their use in Ireland is on an unlicensed basis (Clinical and Experimental Dermatology 37:786-801, 2012). The purpose of this literature review is to evaluate the efficacy and safety of FAEs in the management of moderate to severe psoriasis in adult patients. The reviewer intends to systematically review all available literature on the efficacy and/or safety of fumaric acid esters in the management of moderate to severe psoriasis in adult patients. A systematic review of the literature was performed by one reviewer. The PubMed, TRIP, Embase, and Cochrane Collaboration databases were systematically interrogated to include randomised controlled trials, cohort studies and case studies evaluating the efficacy and/or safety of FAEs in the management of moderate to severe psoriasis in adult patients. Inclusion criteria were studies which included adults over 18 years of age, with a diagnosis of moderate to severe chronic plaque psoriasis, who were treated with FAEs and no other systemic anti-psoriatic agents concurrently. Exclusion criteria were studies involving children, mild psoriasis, studies which did not include patients with chronic plaque psoriasis, the use of FAE for the management of illnesses other than psoriasis, and patients treated with more than one systemic anti-psoriatic agent concurrently. In total 19 articles were selected for review including 2 randomised placebo controlled trials, 1 non-randomised comparative study, 7 retrospective cohort studies, 2 prospective cohort studies and 7 case studies. The findings suggest that FAEs are a safe and effective

  19. ABS polymer electroless plating through a one-step poly(acrylic acid) covalent grafting.

    Science.gov (United States)

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Mesnage, Alice; Jégou, Pascale; Nekelson, Fabien; Roussel, Sébastien; Palacin, Serge

    2010-04-01

    A new, efficient, palladium- and chromium-free process for the electroless plating of acrylonitrile-butadiene-styrene (ABS) polymers has been developed. The process is based on the ion-exchange properties of poly(acrylic acid) (PAA) chemically grafted onto ABS via a simple and one-step method that prevents using classical surface conditioning. Hence, ABS electroless plating can be obtained in three steps, namely: (i) the grafting of PAA onto ABS, (ii) the copper Cu(0) seeding of the ABS surface, and (iii) the nickel or copper metallization using commercial-like electroless plating bath. IR, XPS, and SEM were used to characterize each step of the process, and the Cu loading was quantified by atomic absorption spectroscopy. This process successfully compares with the commercial one based on chromic acid etching and palladium-based seed layer, because the final metallic layer showed excellent adhesion with the ABS substrate.

  20. Pemisahan dan Pemurnian Phthalic Acid Ester dari Minyak Nyamplung

    Directory of Open Access Journals (Sweden)

    William Ekaputra Taifan

    2013-09-01

    Full Text Available Minyak nyamplung dikenal sebagai minyak yang tidak dapat dikonsumsi. Oleh sebab itu, penelitian tentang minyak ini hanya fokus pada konversi minyak menjadi biodiesel. Pada penelitian ini, kami berusaha untuk memisahkan resin beracun dari fraksi metanol menggunakan ekstraksi pelarut diikuti kolom kromatografi. Resin beracun ini diidentifikasi sebagai phthalic acid ester (PAE. PAE ini biasanya digunakan sebagai zat aditif di industri polimer. Minyak nyamplung mengandung 1,8% PAE, yang masih jauh melebihi nilai ambang batas. Isolasi PAE dari minyak ini diharapkan dapt mengubah minyak yang tidak dapat dikonsumsi menjadi suplemen makanan yang bernilai. Proses isolasi PAE dimulai dengan memisahkan senyawa yang diinginkan dari lipid menggunakan ekstraksi pelarut bertingkat dengan metanol dan n-heksan. Analisa mass spectra dari fraksi pertama dan fraksi kedua metanol menunjukkan kandungan PAE sebesar 60% dan 6% pada tiap fraksi. Fraksi heksan tidak mengandung PAE. PAE yang terkandung pada fraksi metanol diisolasi lebih lanjut dari asam lemak menggunakan liquid column chromatography dengan n-heksan – etil asetat sebagai mobile phase. Bis- 2ethylhexyl phthalate diidentifikasi pada ketiga fraksi sesuai dengan hasil analisa GC-MS. Fraksi pertama diambil pada kondisi mobile phase 5% etil asetat, sedangkan fraksi kedua merupakan campuran 5% etil asetat dan 10% etil asetat. Fraksi ketiga diambil pada kondisi mobile phase 10% etil asetat mengandung PAE sebesar 98%. Fraksi keempat merupakan campuran 10% dan 15% mobile phase dan mengandung PAE sebesar 97%. Akhirnya, kandungan PAE pada fraksi metanol sebesar 58%. Dari hasil analisa, dapat disimpulkan bahwa mobile phase yang optimum untuk kromatografi adalah 10- 15% etil asetat dalam n-heksan.

  1. Fumaric Acid Esters Attenuate Secondary Degeneration after Spinal Cord Injury.

    Science.gov (United States)

    Cordaro, Marika; Casili, Giovanna; Paterniti, Irene; Cuzzocrea, Salvatore; Esposito, Emanuela

    2017-11-01

    Spinal cord injury (SCI) causes permanent changes in motor, sensory, and autonomic functions. Unfortunately, there are no stable cures and current treatments include surgical decompression, methylprednisolone, and hemodynamic control that lead to modest function recovery. Fumaric acid esters (FAEs) were firstly used in the management of an immunological skin disorder, such as psoriasis. Because of their potent anti-inflammatory effects, they have been introduced in multiple sclerosis (MS). Investigation has shown not only an anti-inflammatory, but also supposed neuroprotective mechanism of action. The goal of the present work was to evaluate the potential beneficial effects of dimethyl fumarate (DMF) and monomethyl fumarate (MMF) in a mouse model of traumatic SCI. SCI was produced by extradural compression for 1 min of the spinal cord at the T6-7 level using an aneurysm clip, and DMF and MMF (both at 30 mg/kg) were administered by oral gavage to the mice 1 and 6 h after SCI. For locomotor activity, study mice were treated with FAEs once daily for 10 days. We observed that mice treated with DMF exhibited a significant and sustained recovery of motor function. FAEs significantly reduced the severity of inflammation by a modulation of pro-inflammatory cytokines and apoptosis factors, and increased neutrophic factors such as anti-brain-derived neurotrophic factor (BDNF), anti-glial cell-derived neurotrophic factor (GDNF), and neurotrophin-3 (NT3). Our results showed important protective effects of DMF in an animal model of SCI, considerably improving recovery of motor function, possibly by reducing the secondary inflammation and tissue injury that characterize this model. DMF may constitute a promising target for future SCI therapies.

  2. In vitro pharmacokinetics of anti-psoriatic fumaric acid esters

    Science.gov (United States)

    Litjens, Nicolle HR; van Strijen, Elisabeth; van Gulpen, Co; Mattie, Herman; van Dissel, Jaap T; Thio, H Bing; Nibbering, Peter H

    2004-01-01

    Background Psoriasis is a chronic inflammatory skin disease that can be successfully treated with a mixture of fumaric acid esters (FAE) formulated as enteric-coated tablets for oral use. These tablets consist of dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) and its main bioactive metabolite is monomethylfumarate (MMF). Little is known about the pharmacokinetics of these FAE. The aim of the present study was to investigate the hydrolysis of DMF to MMF and the stability of MMF, DMF and MEF at in vitro conditions representing different body compartments. Results DMF is hydrolyzed to MMF in an alkaline environment (pH 8), but not in an acidic environment (pH 1). In these conditions MMF and MEF remained intact during the period of analysis (6 h). Interestingly, DMF was hardly hydrolyzed to MMF in a buffer of pH 7.4, but was rapidly hydrolyzed in human serum having the same pH. Moreover, in whole blood the half-life of DMF was dramatically reduced as compared to serum. The concentrations of MMF and MEF in serum and whole blood decreased with increasing time. These data indicate that the majority of the FAE in the circulation are metabolized by one or more types of blood cells. Additional experiments with purified blood cell fractions resuspended in phosphate buffered saline (pH 7.4) revealed that at concentrations present in whole blood monocytes/lymphocytes, but not granulocytes and erythrocytes, effectively hydrolyzed DMF to MMF. Furthermore, in agreement with the data obtained with the pure components of the tablet, the enteric-coated tablet remained intact at pH 1, but rapidly dissolved at pH 8. Conclusion Together, these in vitro data indicate that hydrolysis of DMF to MMF rapidly occurs at pH 8, resembling that within the small intestines, but not at pH 1 resembling the pH in the stomach. At both pHs MMF and MEF remained intact. These data explain the observation that after oral FAE intake MMF and MEF, but not DMF, can be readily detected in the

  3. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid, alkyl and substituted... Significant New Uses for Specific Chemical Substances § 721.1875 Boric acid, alkyl and substituted alkyl... chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to reporting...

  4. Selected Gamma Aminobutyric Acid (GABA Esters may Provide Analgesia for Some Central Pain Conditions

    Directory of Open Access Journals (Sweden)

    Joel S. Goldberg

    2010-08-01

    Full Text Available Central pain is an enigmatic, intractable condition, related to destruction of thalamic areas, resulting in likely loss of inhibitory synaptic transmission mediated by GABA. It is proposed that treatment of central pain, a localized process, may be treated by GABA supplementation, like Parkinson’s disease and depression. At physiologic pH, GABA exists as a zwitterion that is poorly permeable to the blood brain barrier (BBB. Because the pH of the cerebral spinal fluid (CSF is acidic relative to the plasma, ion trapping may allow a GABA ester prodrug to accumulate and be hydrolyzed within the CSF. Previous investigations with ester local anesthetics may be applicable to some GABA esters since they are weak bases, hydrolyzed by esterases and cross the BBB. Potential non-toxic GABA esters are discussed. Many GABA esters were investigated in the 1980s and it is hoped that this paper may spark renewed interest in their development.

  5. Polymers from amino acids: development of dual ester-urethane melt condensation approach and mechanistic aspects.

    Science.gov (United States)

    Anantharaj, S; Jayakannan, M

    2012-08-13

    A new dual ester-urethane melt condensation methodology for biological monomers-amino acids was developed to synthesize new classes of thermoplastic polymers under eco-friendly and solvent-free polymerization approach. Naturally abundant L-amino acids were converted into dual functional ester-urethane monomers by tailor-made synthetic approach. Direct polycondensation of these amino acid monomers with commercial diols under melt condition produced high molecular weight poly(ester-urethane)s. The occurrence of the dual ester-urethane process and the structure of the new poly(ester-urethane)s were confirmed by (1)H and (13)C NMR. The new dual ester-urethane condensation approach was demonstrated for variety of amino acids: glycine, β-alanine, L-alanine, L-leucine, L-valine, and L-phenylalanine. MALDI-TOF-MS end group analysis confirmed that the amino acid monomers were thermally stable under the melt polymerization condition. The mechanism of melt process and the kinetics of the polycondensation were studied by model reactions and it was found that the amino acid monomer was very special in the sense that their ester and urethane functionality could be selectively reacted by polymerization temperature or catalyst. The new polymers were self-organized as β-sheet in aqueous or organic solvents and their thermal properties such as glass transition temperature and crystallinity could be readily varied using different l-amino acid monomers or diols in the feed. Thus, the current investigation opens up new platform of research activates for making thermally stable and renewable engineering thermoplastics from natural resource amino acids.

  6. Electrokinetic characterization of poly(acrylic acid) and poly(ethylene oxide) brushes in aqueous electrolyte solutions

    NARCIS (Netherlands)

    Zimmermann, R.; Norde, W.; Cohen Stuart, M.A.; Werner, C.

    2005-01-01

    Surfaces carrying hydrophilic polymer brushes were prepared from poly(styrene)-poly(acrylic acid) and poly(styrene)-poly(ethylene oxide) diblock copolymers, respectively, using a Langmuir-Blodgett technique and employing poly(styrene)-coated planar glass as substrates. The electrical properties of

  7. The copolimeryzation synthesis and swelling capacity of cellulose-poly superabsorbent (acrylic acid-co-acrylamide) based on rice straw

    Science.gov (United States)

    Helmiyati; Fitriyani, A.; Meyanti, F.

    2017-04-01

    A superabsorbent has been synthesized by copolymerization of rice straw cellulose as the back bone with the composition of 0.724 mol/L acrylamide and 1.429 mol/L acrylic acid as the monomers, 2.32 mmol/L N, N‧-methylene-bis-acrylamide as the crosslinker, and 7.94 mmol/L potassium persulfate as the initiator. The rendement of cellulose obtained from rice straw isolation is 33.55% with the size of 34.06 nm nanocrystalline cellulose, obtained from XRD diffraction pattern. The copolymerization results in the spectrum characterization of Cellulose-Poly superabsorbent (AA-co-AM) with FTIR shows OH stretching vibration, NH and C=O stretching of monomer acrylic acid and acrylamide at wave number about 3343 cm-1 and 1600 cm-1. The surface morphology analyzed with SEM shows the superabsorbent has rough surface morphology compared to acrylic acid-acrylamide copolymer. The results of grafting efficiency increases with the increasing amount of the reacted monomer. The characterization of result shows that the grafting process of acrylic acid-acrylamide on cellulose has been formed. The swelling capacity of superabsorbent in water is 691.18 g/g, and 765.58 g/g in urea. This result is quite satisfactory and can be applied for slow release superabsorbent.

  8. Introduction of poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid)] branches onto starch for cotton warp sizing.

    Science.gov (United States)

    Shen, Shiqi; Zhu, Zhifeng; Liu, Fengdan

    2016-03-15

    An attempt has been made to reveal the effect of amphoteric poly(2-acryloyloxyethyl trimethyl ammonium chloride-co-acrylic acid) [P(ATAC-co-AA)] branches grafted onto the backbones of starch upon the adhesion-to-cotton, film properties, and desizability of maize starch for cotton warp sizing. Starch-g-poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid) [S-g-P(ATAC-co-AA)] was prepared by the graft copolymerization of 2-acryloyloxyethyl trimethyl ammonium chloride (ATAC) and acrylic acid (AA) with acid-converted starch (ACS) in aqueous medium using Fe(2+)-H2O2 initiator. The adhesion was evaluated in term of bonding strength according to the FZ/T 15001-2008 whereas the film properties considered included tensile strength, work and percentage elongation at break. The evaluation was undertaken through the comparison of S-g-P(ATAC-co-AA) with ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride). It was found that the amphoteric branch was able to significantly improve the adhesion and mitigate the brittleness of starch film. Zeta potential of cooked S-g-P(ATAC-co-AA) paste, depending on the mole ratio of ATAC to AA units on P(ATAC-co-AA) branches, had substantial effect on the adhesion and desizability. Increasing the mole ratio raised the potential, which favored the adhesion but disfavored the removal of S-g-P(ATAC-co-AA) from sized cotton warps. Electroneutral S-g-P(ATAC-co-AA) was superior to negatively grafted starch in adhesion and to positively grafted starch in desizability. Generally, it showed better sizing property than ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride), and had potential in the application of cotton warp sizing. Copyright © 2015. Published by Elsevier Ltd.

  9. Michael-type addition of azoles of broad-scale acidity to methyl acrylate

    Directory of Open Access Journals (Sweden)

    Krzysztof Z. Walczak

    2011-02-01

    Full Text Available An optimisation of Michael-type addition of azole derivatives of broad-scale acidity – ranging from 5.20 to 15.00 pKa units – namely 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5-nitroimidazole, 5(4-bromo-2-methyl-4(5-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the use of an appropriate basic catalyst (DBU, DIPEA, NaOH, NaH, TEDA, a donor/base/acceptor ratio and the reaction temperature. The reactions were performed in DMF as solvent. Target Michael adducts were obtained in medium to excellent yields. Importantly, for imidazole and 1,2,4-triazole derivatives, no corresponding regioisomers were obtained.

  10. Dyes adsorption using a synthetic carboxymethyl cellulose-acrylic acid adsorbent.

    Science.gov (United States)

    Zhang, Genlin; Yi, Lijuan; Deng, Hui; Sun, Ping

    2014-05-01

    Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning electron microscopy and Fourier-transform infrared spectroscopy verified the adsorbent formed under optimized reaction conditions. The removal ratio of adsorbent to Methyl Orange, Disperse Blue 2BLN and malachite green chloride reached to 84.2%, 79.6% and 99.9%, respectively. The greater agreement between the calculated and experimental results suggested that pseudo second-order kinetic model better represents the kinetic adsorption data. Equilibrium adsorptions of dyes were better explained by the Temkin isotherm. The results implied that this new cellulose-based absorbent had the universality for removal of dyes through the chemical adsorption mechanism. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  11. Properties of the acrylic acid polymers obtained by atmospheric pressure plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Topala, Ionut [Plasma Physics Laboratory, Faculty of Physics, Al. I. Cuza University, 11 Carol I Boulevard, 700506 Iasi (Romania)], E-mail: itopala@plasma.uaic.ro; Dumitrascu, Nicoleta; Popa, Gheorghe [Plasma Physics Laboratory, Faculty of Physics, Al. I. Cuza University, 11 Carol I Boulevard, 700506 Iasi (Romania)

    2009-01-15

    Plasma polymers of acrylic acid were obtained using an atmospheric pressure discharge system. The plasma polymerization reactor uses a dielectric barrier discharge, with the polyethylene terephthalate dielectric acting as substrate for deposition. The plasma was characterized by specific electrical measurements, monitoring the applied voltage and the discharge current. Based on the spatially resolved optical emission spectroscopy, we analyzed the distribution of the excited species in the discharge gap, specific plasma temperatures (vibrational and gas temperatures) being calculated with the Boltzmann plot method. The properties of the plasma polymer films were investigated by contact angle measurements, infrared and UV-Vis spectroscopy, scanning electron microscopy. The films produced by plasma polymerization at atmospheric pressure showed a hydrophilic character, in correlation with the strong absorbance of OH groups in the FTIR spectrum. Moreover, the surface of the plasma polymers at micrometric scale is smooth and free of defects without particular features.

  12. Poly(acrylic acid surface grafted polypropylene films: Near surface and bulk mechanical response

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Radical photo-grafting polymerization constitutes a promising technique for introducing functional groups onto surfaces of polypropylene films. According to their final use, surface grafting should be done without affecting overall mechanical properties. In this work the tensile drawing, fracture and biaxial impact response of biaxially oriented polypropylene commercial films grafted with poly(acrylic acid (PAA were investigated in terms of film orientation and surface modification. The variations of surface roughness, elastic modulus, hardness and resistance to permanent deformation induced by the chemical treatment were assessed by depth sensing indentation. As a consequence of chemical modification the optical, transport and wettability properties of the films were successfully varied. The introduced chains generated a PAA-grafted layer, which is stiffer and harder than the neat polypropylene surface. Regardless of the surface changes, it was proven that this kind of grafting procedure does not detriment bulk mechanical properties of the PP film.

  13. Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Arumugham Suresh

    2014-09-01

    Full Text Available Objective: To evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. Methods: Antimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp., Candida sp., and Aspergillus niger and Aspergillus flavus. The FAME profiles were determined through gas chromatography with a flame ionization detector. Results: The FAME was found to be radial effective in inhibiting the radial growth of both bacterial and fungal pathogens. The FAME extracts exhibited the antibacterial activity against three clinical pathogens, namely, Escherichia coli, Salmonella typhi and Enterobacter sp. with the maximum zone of inhibition of 12.0 mm, 12.0 mm and 11.0 mm, respectively. The FAME showed moderate antifungal activity against Cryptococcus sp. (11.8 mm, Aspergillus niger (10.5 mm, Candida sp. (11.8 mm and Fusarium sp. (10.4 mm. Gas chromatography-flame ionization detector analysis revealed about 30 different FAMEs. Conclusions: We assume that the observed antimicrobial potency may be due to the abundance of erucic acid methyl ester (C22:0, arachidic acid methyl ester (C20:0, palmitic acid methyl ester (C16:0, cis-11-eicosenoicmethyl ester (C20:1, cis-11, 14-eicosadienoic acid methyl ester (C20:2 and linolenic acid methyl ester (C18:3 in FAMEs which appears to be promising to treat microbial diseases.

  14. Analysis of chemical signatures of alkaliphiles using fatty acid methyl ester analysis

    Directory of Open Access Journals (Sweden)

    Basha Sreenivasulu

    2017-01-01

    Full Text Available Background: Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. Materials and Methods: To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS analysis. Results: The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. Conclusions: These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic.

  15. Analysis of Chemical Signatures of Alkaliphiles using Fatty Acid Methyl Ester Analysis.

    Science.gov (United States)

    Sreenivasulu, Basha; Paramageetham, Chinthala; Sreenivasulu, Dasari; Suman, Bukke; Umamahesh, Katike; Babu, Gundala Prasada

    2017-01-01

    Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS) analysis. The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl) ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  17. Design of psyllium-PVA-acrylic acid based novel hydrogels for use in antibiotic drug delivery.

    Science.gov (United States)

    Singh, Baljit; Sharma, Vikrant

    2010-04-15

    In order to exploit the potential of gel forming medicinally important polysaccharide, we have developed psyllium based hydrogels through graft copolymerization. The optimum conditions for the synthesis of psyllium-poly(vinyl alcohol) (PVA)-poly(acrylic acid) blended hydrogels have been evaluated and their characterization has been carried out by SEMs, FTIR and swelling studies. The optimum conditions for the synthesis of hydrogels have been obtained as 1% (v/v) acrylic acid, 2% (w/v) PVA and 1g of psyllium. The use of very small amount of these petroleum products has developed the low energy, cost effective, biodegradable and biocompatible material for potential biomedical applications. It is the novelty of the present finding. The release of model antibiotic drug tetracycline HCl from the hydrogels has been observed more in pH 2.2 buffer hence these hydrogels are suitable for peptic ulcer caused by Helicobacter pylori. At the same time psyllium has also been reported to cure the ulcerative colitis. Hence, the present drug delivery system will have double potential to cure ulcer. The values of the diffusion exponent for the release of drug have been obtained as (0.774, 0.576 and 0.858) and gel characteristic constant have been (8.884x10(-3), 24.149x10(-3) and 3.989x10(-3)) respectively in pH 2.2 buffer, 7.4 buffer and distilled water. The release of the drug from the hydrogels occurred through non-Fickian diffusion mechanism. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Gamma-aminobutyric acid esters. 1. Synthesis, brain uptake, and pharmacological studies of aliphatic and steroid esters of gamma-aminobutyric acid

    Energy Technology Data Exchange (ETDEWEB)

    Shashoua, V.E.; Jacob, J.N.; Ridge, R.; Campbell, A.; Baldessarini, R.J.

    1984-05-01

    Labeled and unlabeled aliphatic and steroid esters of gamma-amino(U-/sup 14/C)butyric acid (GABA) were synthesized and tested for their capacity to penetrate the blood-brain barrier and for evidence of central neuropharmacological activity in rodents. The uptake of the labeled 9,12,15-octadecatrienyl (linolenyl), 3-cholesteryl, 1-butyl, and the 9-fluoro-11 beta,17-dihydroxy-16 alpha-methyl-3,20-dioxopregna -1,4-dien-21-yl (dexamethasone) esters of GABA into mouse brain increased 2-, 25-, 74-, and 81-fold over GABA, respectively. The cholesteryl ester of GABA depressed the general motor activity of mice and rats in a dose-dependent manner, whereas the 1-butyl, linolenyl, and dexamethasone esters were inactive by this test. Studies of the rates of hydrolysis, GABA receptor binding capacity, and octanol/water partition coefficients indicated that pharmacological activity of the esters after entry into the central nervous system (CNS) was dependent on their capacity to release GABA by enzymatic hydrolysis and their lipid solubility.

  19. Gamma-aminobutyric acid esters. 1. Synthesis, brain uptake, and pharmacological studies of aliphatic and steroid esters of gamma-aminobutyric acid.

    Science.gov (United States)

    Shashoua, V E; Jacob, J N; Ridge, R; Campbell, A; Baldessarini, R J

    1984-05-01

    Labeled and unlabeled aliphatic and steroid esters of gamma-amino[U-14C]butyric acid (GABA) were synthesized and tested for their capacity to penetrate the blood-brain barrier and for evidence of central neuropharmacological activity in rodents. The uptake of the labeled 9,12,15- octadecatrienyl ( linolenyl ), 3-cholesteryl, 1-butyl, and the 9-fluoro-11 beta,17-dihydroxy-16 alpha-methyl-3,20- dioxopregna -1,4-dien-21-yl (dexamethasone) esters of GABA into mouse brain increased 2-, 25-, 74-, and 81-fold over GABA, respectively. The cholesteryl ester of GABA depressed the general motor activity of mice and rats in a dose-dependent manner, whereas the 1-butyl, linolenyl , and dexamethasone esters were inactive by this test. Studies of the rates of hydrolysis, GABA receptor binding capacity, and octanol/water partition coefficients indicated that pharmacological activity of the esters after entry into the central nervous system (CNS) was dependent on their capacity to release GABA by enzymatic hydrolysis and their lipid solubility.

  20. SPECTROSCOPIC STUDY ON POLY(ACRYLIC ACID-CO-ACRYLAMIDE)-GRAFT-POLYANILINE AS A RADIATION DOSIMETER FOR ALPHA PARTICLES.

    Science.gov (United States)

    Abd El-Mageed, H R; Abd El-Salam, H M; Eissa, M F

    2017-08-31

    Poly(acrylate-co-acrylamide) was a synthesis by chemical oxidation polymerization of an aqueous binary mixture of acrylate/acrylamide (1:1 mole ratio) using ammonium persulphate as an initiator at 70°C under the nitrogen atmosphere. The obtained copolymer was introduced for grafting with polyaniline. The grafting process was performed by chemical oxidation polymerization of aniline using ammonium persulphate as an initiator in hydrochloric acid media at 40°C under the nitrogen atmosphere. Poly(acrylic acid-co-acrylamide)-graft-polyaniline samples irradiated with (alpha-particles) at different irradiation doses (0, 2.33, 8.73, 13.09 and 17.46 Gy) at the same linear energy transfer. The change in the morphology, optical properties and the energy gap of poly(acrylic acid-co-acrylamide)-graft-polyaniline samples were studied. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Novel Approach: Tungsten Oxide Nanoparticle as a Catalyst for Malonic Acid Ester Synthesis via Ozonolysis

    Directory of Open Access Journals (Sweden)

    Bilal A. Wasmi

    2014-01-01

    Full Text Available Malonic acid ester was synthesized via the one-step ozonolysis of palm olein. Malonic acid ester was spectroscopically characterized using gas chromatography mass spectroscopy (GC-MS. Tungsten oxide nanoparticles were used as the catalyst, which was characterized via X-ray powder diffraction (XRD and field emission scanning electron microscopy (FE-SEM. Tungsten oxide provided several advantages as a catalyst for the esterification malonic acid such as simple operation for a precise ozonation method, an excellent yield of approximately 10%, short reaction times of 2 h, and reusability due to its recyclability.

  2. One-step formation of multiple Pickering emulsions stabilized by self-assembled poly(dodecyl acrylate-co-acrylic acid) nanoparticles.

    Science.gov (United States)

    Zhu, Ye; Sun, Jianhua; Yi, Chenglin; Wei, Wei; Liu, Xiaoya

    2016-09-13

    In this study, a one-step generation of stable multiple Pickering emulsions using pH-responsive polymeric nanoparticles as the only emulsifier was reported. The polymeric nanoparticles were self-assembled from an amphiphilic random copolymer poly(dodecyl acrylate-co-acrylic acid) (PDAA), and the effect of the copolymer content on the size and morphology of PDAA nanoparticles was determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The emulsification study of PDAA nanoparticles revealed that multiple Pickering emulsions could be generated through a one-step phase inversion process by using PDAA nanoparticles as the stabilizer. Moreover, the emulsification performance of PDAA nanoparticles at different pH values demonstrated that multiple emulsions with long-time stability could only be stabilized by PDAA nanoparticles at pH 5.5, indicating that the surface wettability of PDAA nanoparticles plays a crucial role in determining the type and stability of the prepared Pickering emulsions. Additionally, the polarity of oil does not affect the emulsification performance of PDAA nanoparticles, and a wide range of oils could be used as the oil phase to prepare multiple emulsions. These results demonstrated that multiple Pickering emulsions could be generated via the one-step emulsification process using self-assembled polymeric nanoparticles as the stabilizer, and the prepared multiple emulsions have promising potential to be applied in the cosmetic, medical, and food industries.

  3. Inhibitory effects of caffeic acid phenethyl ester derivatives on replication of hepatitis C virus.

    Directory of Open Access Journals (Sweden)

    Hui Shen

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

  4. Synthesis and antiproliferative properties of new hydrophilic esters of triterpenic acids

    Czech Academy of Sciences Publication Activity Database

    Eignerová, Barbara; Tichý, Michal; Krasulová, Jana; Kvasnica, Miroslav; Rárová, L.; Christová, R.; Urban, M.; Bednarczyk-Cwynar, B.; Hajdúch, M.; Šarek, J.

    2017-01-01

    Roč. 140, Nov 10 (2017), s. 403-420 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 ; RVO:61389030 Keywords : cytotoxicity * triterpenic acids * betulinic acid * hydrophilic ester * prodrug Subject RIV: CC - Organic Chemistry Impact factor: 4.519, year: 2016

  5. Alcohol consumption and synthesis of ethyl esters of fatty acids in adipose tissue

    NARCIS (Netherlands)

    Björntorp, P; Depergola, G; Sjöberg, C; Pettersson-Kymmer, U.; Hallgren, P; Boström, K; Helander, K G; Seidell, J

    1990-01-01

    Ethyl esters of fatty acids (EEFA) have been found to be formed during ethanol metabolism. Human adipose tissue contains high concentrations of free fatty acids, the substrate for EEFA synthesis, and might therefore be a tissue with great potential for EEFA formation. In order to explore their

  6. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid...... methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  7. Production of acrylic acid and propionic acid by constructing a portion of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula in Escherichia coli.

    Science.gov (United States)

    Liu, Zhijie; Liu, Tiangang

    2016-12-01

    Acrylic acid and propionic acid are important chemicals requiring affordable, renewable production solutions. Here, we metabolically engineered Escherichia coli with genes encoding components of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula for conversion of glucose to acrylic and propionic acids. To construct an acrylic acid-producing pathway in E. coli, heterologous expression of malonyl-CoA reductase (MCR), malonate semialdehyde reductase (MSR), 3-hydroxypropionyl-CoA synthetase (3HPCS), and 3-hydroxypropionyl-CoA dehydratase (3HPCD) from M. sedula was accompanied by overexpression of succinyl-CoA synthetase (SCS) from E. coli. The engineered strain produced 13.28 ± 0.12 mg/L of acrylic acid. To construct a propionic acid-producing pathway, the same five genes were expressed, with the addition of M. sedula acryloyl-CoA reductase (ACR). The engineered strain produced 1430 ± 30 mg/L of propionic acid. This approach can be expanded to synthesize many important organic chemicals, creating new opportunities for the production of chemicals by carbon dioxide fixation.

  8. Unsaturated Fatty Acid Esters Metathesis Catalyzed by Silica Supported WMe5

    KAUST Repository

    Riache, Nassima

    2015-11-14

    Metathesis of unsaturated fatty acid esters (FAEs) by silica supported multifunctional W-based catalyst is disclosed. This transformation represents a novel route towards unsaturated di-esters. Especially, the self-metathesis of ethyl undecylenate results almost exclusively on the homo-coupling product whereas with such catalyst, 1-decene gives ISOMET (isomerization and metathesis olefin) products. The olefin metathesis in the presence of esters is very selective without any secondary cross-metathesis products demonstrating that a high selective olefin metathesis could operate at 150 °C. Additionally, a cross-metathesis of unsaturated FAEs and α-olefins allowed the synthesis of the corresponding ester with longer hydrocarbon skeleton without isomerisation.

  9. Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

    DEFF Research Database (Denmark)

    Hinge, Mogens; Keiding, Kristian

    2006-01-01

    by titration, dynamic light scattering (DLS), scanning electron microscopy (SEM) and transition electron microscopy (TEM).   The acrylic acid was fully incorporated into the poly(ST-co-AA) colloids in blocks and/or clusters and the purified poly(ST-co-AA) colloids swelled when pH was changed from low (4......) to high (10). There was a linear correlation between the incorporated amount of acrylic acid and the swelling for the purified poly(ST-co-AA) colloids. The swelling is thus ascribed to ionization of poly(acrylic acid). Samples were taken during synthesis and the fractional conversion and size...

  10. A Lewis Base Catalysis Approach for the Photoredox Activation of Boronic Acids and Esters.

    Science.gov (United States)

    Lima, Fabio; Sharma, Upendra K; Grunenberg, Lars; Saha, Debasmita; Johannsen, Sandra; Sedelmeier, Joerg; Van der Eycken, Erik V; Ley, Steven V

    2017-11-20

    We report herein the use of a dual catalytic system comprising a Lewis base catalyst such as quinuclidin-3-ol or 4-dimethylaminopyridine and a photoredox catalyst to generate carbon radicals from either boronic acids or esters. This system enabled a wide range of alkyl boronic esters and aryl or alkyl boronic acids to react with electron-deficient olefins via radical addition to efficiently form C-C coupled products in a redox-neutral fashion. The Lewis base catalyst was shown to form a redox-active complex with either the boronic esters or the trimeric form of the boronic acids (boroxines) in solution. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Esterification Reaction of Glycerol and Palm Oil Oleic Acid Using Methyl Ester Sulfonate Acid Catalyst as Drilling Fluid Formulation

    Science.gov (United States)

    Sari, V. I.; Hambali, E.; Suryani, A.; Permadi, P.

    2017-02-01

    Esterification reaction between glycerol with palm oil oleic acid to produce glycerol ester and one of the utilization of glycerol esters is as ingredients of drilling fluids formula for oil drilling needs. The purpose of this research is to get the best conditions of the esterification process. The esterification reaction does with the reactants is glycerol with purity of 97.6%, palm oil oleic acid with the molar ratio is 1:1, Methyl Ester Sulfonate Acid (MESA) catalyst 0.5%, and stirring speed 400 rpm. The temperature range of 180°C to 240°C and the processing time between 120 to 180 minutes. The results showed that the best conditions of the esterification reaction at the temperature 240°C and time process are 180 minute. The increasing temperature resulted that the acid number decreases and causing the conversion increased. The maximum conversion is 99.24%, density 0.93 g/cm3, flash point 241°C, pour point -3°C, the boiling point of 244 °C, the acid value of 1.90 mg KOH/g sample, kinematic viscosity 31.51 cSt (40°C), surface tension 37.0526 dyne/cm and GCMS identification, glycerol ester at 22,256 retention time (minutes) and wide area 73.75 (%). From the research results obtained glycerol ester with characteristics suitable for drilling fluid formulations.

  12. Fatty acid esters produced by Lasiodiplodia theobromae function as growth regulators in tobacco seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Uranga, Carla C., E-mail: curanga@cicese.edu.mx [Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada-Tijuana 3918, Zona Playitas, 22860 Ensenada, B.C. (Mexico); Beld, Joris, E-mail: joris.beld@drexelmed.edu [University of California, San Diego, Department of Chemistry and Biochemistry, 9500 Gilman Dr., La Jolla, CA 92093-0358 (United States); Mrse, Anthony, E-mail: amrse@ucsd.edu [University of California, San Diego, Department of Chemistry and Biochemistry, 9500 Gilman Dr., La Jolla, CA 92093-0358 (United States); Córdova-Guerrero, Iván, E-mail: icordova@uabc.edu.mx [Universidad Autónoma de Baja California (UABC), Calzada Universidad 14418 Parque Industrial Internacional Tijuana, Tijuana, B.C. 22390 (Mexico); Burkart, Michael D., E-mail: mburkart@ucsd.edu [University of California, San Diego, Department of Chemistry and Biochemistry, 9500 Gilman Dr., La Jolla, CA 92093-0358 (United States); Hernández-Martínez, Rufina, E-mail: ruhernan@cicese.mx [Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada-Tijuana 3918, Zona Playitas, 22860 Ensenada, B.C. (Mexico)

    2016-04-01

    The Botryosphaeriaceae are a family of trunk disease fungi that cause dieback and death of various plant hosts. This work sought to characterize fatty acid derivatives in a highly virulent member of this family, Lasiodiplodia theobromae. Nuclear magnetic resonance and gas chromatography-mass spectrometry of an isolated compound revealed (Z, Z)-9,12-ethyl octadecadienoate, (trivial name ethyl linoleate), as one of the most abundant fatty acid esters produced by L. theobromae. A variety of naturally produced esters of fatty acids were identified in Botryosphaeriaceae. In comparison, the production of fatty acid esters in the soil-borne tomato pathogen Fusarium oxysporum, and the non-phytopathogenic fungus Trichoderma asperellum was found to be limited. Ethyl linoleate, ethyl hexadecanoate (trivial name ethyl palmitate), and ethyl octadecanoate, (trivial name ethyl stearate), significantly inhibited tobacco seed germination and altered seedling leaf growth patterns and morphology at the highest concentration (0.2 mg/mL) tested, while ethyl linoleate and ethyl stearate significantly enhanced growth at low concentrations, with both still inducing growth at 98 ng/mL. This work provides new insights into the role of naturally esterified fatty acids from L. theobromae as plant growth regulators with similar activity to the well-known plant growth regulator gibberellic acid. - Highlights: • Lasiodiplodia theobromae produces a wide variety of fatty acid esters in natural substrates. • Ethyl stearate and ethyl linoleate inhibit tobacco germination at 0.2 mg/mL. • Ethyl stearate and ethyl linoleate induce tobacco germination at 98 ng/mL. • Tobacco growth increase in ethyl stearate and ethyl linoleate parallels gibberellic acid. • A role as plant growth regulators is proposed for fatty acid esters.

  13. Nanocapsule of cationic liposomes obtained using "in situ" acrylic acid polymerization: stability, surface charge and biocompatibility.

    Science.gov (United States)

    Scarioti, Giovana Danieli; Lubambo, Adriana; Feitosa, Judith P A; Sierakowski, Maria Rita; Bresolin, Tania M B; de Freitas, Rilton Alves

    2011-10-15

    In this work, didecyldimethylammonium bromide (DDAB) and 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) (2.5:1) were used to prepare liposomes coated with polyacrylic acid (PAA) using "in situ" polymerization with 2.5, 5 and 25 mM of acrylic acid (AA). The PAA concentrations were chosen to achieve partially to fully covered capsules, and the polymerization reaction was observed with real-time monitoring using dynamic light scattering (NanoDLS). The DDAB:DOPE liposomes showed stability in the tested temperature range (25-70°C), whereas the results confirmed the success of the polymerization according to superficial charge (zeta potential of +66.7±1.2 mV) results and AFM images. For the liposomes that were fully coated with PAA (zeta potential of +0.3±3.9 mV), cytotoxicity was independent of the concentration of albumin. Cationic liposomes and nanocapsules of the stable liposomes coated with PAA were obtained by controlling the surface charge, which was the most important factor related to cytotoxicity. Thus, a potential, safe drug nanocarrier was successfully developed in this work. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Ultra-Thin Films of Poly(acrylic acid/Silver Nanocomposite Coatings for Antimicrobial Applications

    Directory of Open Access Journals (Sweden)

    Alaa Fahmy

    2016-01-01

    Full Text Available In this work not only colloids of poly(acrylic acid (PAA embedded with silver nanoparticles (Ag-NPs but thin films (10 nm also were deposited using electrospray deposition technique (ESD. A mixture of sodium borohydride (NaBH4 and ascorbic acid (AA were utilized to reduce the silver ions to generate Ag-NPs in the PAA matrix. Moreover, sodium tricitrate was used to stabilize the prepared colloids. The obtained colloids and films were characterized using UV-visible, transmission electron microscopy (TEM. UV-Vis results reveal that an absorption peak at 425 nm was observed in presence of PAA-AgNO3-AA-citrate-NaBH4. This peak is attributed to the well-known surface plasmon resonance of the silver bound in Ag-NPs, while the reduction was rendering and/or inhibiting in absence of the AA and citrate. FTIR spectroscopy was used to study the mechanism of the reaction process of silver nitrate with PAA. TEM images showed the well dispersion of Ag-NPs in the PAA matrix with average particle size of 8 nm. The antimicrobial studies showed that the Ag-NPs embedded in the PAA matrix have proven to have a significant antimicrobial activity against E. coli, B. subtilis, and C. albicans.

  15. Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Zhihui [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Wang, Zhihua [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (China); Sun, Lei, E-mail: sunlei@henu.edu.cn [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie [Key Laboratory of Cellular and Molecular Immunology, Henan University, Kaifeng 475004 (China); Zhao, Yanbao [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2014-08-01

    Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible absorption spectroscopy (UV–vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. - Highlights: • Dispersed Ag/PAA NPs with small size were synthesized. • Ag/PAA NPs exhibited excellent antimicrobial properties. • Interaction mechanism between Ag/PAA NPs and bacteria was verified.

  16. Homo- and co-polymerization of polysytrene-block-poly(acrylic acid)-coated metal nanoparticles.

    Science.gov (United States)

    Wang, Hong; Song, Xiaohui; Liu, Cuicui; He, Jiating; Chong, Wen Han; Chen, Hongyu

    2014-08-26

    Amphiphilic block copolymers such as polystyrene-block-poly(acrylic acid) (PSPAA) give micelles that are known to undergo sphere-to-cylinder shape transformation. Exploiting this polymer property, core-shell nanoparticles coated in PSPAA can be "polymerized" into long chains following the chain-growth polymerization mode. This method is now extended to include a variety of different nanoparticles. A case study on the assembly process was carried out to understand the influence of the PAA block length, the surface ligand, and the size and morphology of the monomer nanoparticles. Shortening the PAA block promotes the reorganization of the amphiphilic copolymer in the micelles, which is essential for assembling large Au nanoparticles. Small Au nanoparticles can be directly "copolymerized" with empty PSPAA micelles into chains. The reaction time, acid quantity, and the [Au nanoparticles]/[PSPAA micelles] concentration ratio played important roles in controlling the sphere-cylinder-vesicle conversion of the PSPAA micelles, giving rise to different kinds of random "copolymers". With this knowledge, a general method is then developed to synthesize homo, random, and block "copolymers", where the basic units include small Au nanoparticles (d = 16 nm), large Au nanoparticles (d = 32 nm), Au nanorods, Te nanowires, and carbon nanotubes. Given the lack of means for assembling nanoparticles, advancing synthetic capabilities is of crucial importance. Our work provides convenient routes for combining nanoparticles into long-chain structures, facilitating rational design of complex nanostructures in the future.

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

    Science.gov (United States)

    Madl, Tobias; Mittelbach, Martin

    2005-04-01

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

  18. Scalable preparation of high purity rutin fatty acid esters following enzymatic synthesis

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Investigations into expanded uses of modified flavonoids are often limited by the availability of these high purity compounds. As such, a simple, effective and relatively fast method for isolation of gram quantities of both long and medium chain fatty acid esters of rutin following scaled-up bios...... following a two-step solvent purification procedure whereby excess fatty acid substrate was first removed in a heptane/water (4:1, v/v) system, followed by selective ester extraction using an ethyl acetate/water system (1:6, v/v) at elevated temperature....

  19. Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

    Directory of Open Access Journals (Sweden)

    Iurii S. Bodachivskyi

    2016-12-01

    Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

  20. Synthesis of some monocyclic analogues of mycophenolic acid via the Johnson ortho ester Claisen rearrangement.

    Science.gov (United States)

    Meza-Aviña, Ma Elena; Ordoñez, Mario; Fernández-Zertuche, Mario; Rodríguez-Fragoso, Lourdes; Reyes-Esparza, Jorge; de Los Ríos-Corsino, Abril A Martínez

    2005-12-01

    The synthesis of some monocyclic analogues of mycophenolic acid in which the lactone ring has been eliminated, leaving the aromatic ring intact and the same oxygenated substituents flanking the hexenoic acid side chain with an (E)-geometry at the double bond, has been accomplished via the Johnson ortho ester Claisen rearrangement. The synthetic methodology reported here allows the preparation of mycophenolic acid analogues bearing alkyl substituents at the alpha- and beta-positions on the side chain.

  1. Fumaric Acid and its Esters: An Emerging Treatment for Multiple Sclerosis

    OpenAIRE

    Moharregh-Khiabani, D.; Linker, R. A.; Gold, R.; Stangel, M.

    2009-01-01

    Fumaric acid is an intermediate product of the citric acid cycle that is a source of intracellular energy in the form of adenosine triphosphate (ATP). It is generated by oxidation of adenylsuccinate by the enzyme succinate dehydrogenase and is then converted to maleate by the enzyme fumarase. At present, fumaric acid esters (FAE) are licensed for the treatment of psoriasis. Several lines of evidence have demonstrated immunomodulatory effects for FAE. Clinical studies in psoriasis showed a red...

  2. Preparation of 9-hydroxynonanoic acid methyl ester by ozonolysis of vegetable oils and its polycondensation

    Directory of Open Access Journals (Sweden)

    Cvetković Ivana

    2008-01-01

    Full Text Available Vegetable oil-based and potentially biodegradable polyesters were prepared from 9-hydroxynonanoic acid methyl ester. This paper describes ozonolysis of vegetable oils and the method for preparation of useful monomers and in particular 9-hydroxynonanoic acid methyl ester. Ozonolysis of soybean oil and castor oil in methanol and methylene chloride solution, followed by reduction with sodium borohydride was used to obtain a mixture of triols, diols and monols. Triglyceride triols were separated from the rest of the mixture and transesterified with methanol to obtain methyl esters of fatty acids and glycerin. The main component of fatty acids was 9-hydroxynonanoic acid methyl ester, which was characterized and used for polycondensation by transesterification. High molecular weight polyhydroxy alcanoate was a solid having a melting point of 75°C. The molecular weight of the resulting polyester was affected by the purity of the monomer and side reactions such as cyclization. The polymer was characterized by chromatographic, thermal and analytical methods.

  3. Electrical, dielectric and electrochemical characterization of novel poly(acrylic acid)-based polymer electrolytes complexed with lithium tetrafluoroborate

    Science.gov (United States)

    Ngai, Koh Sing; Ramesh, S.; Ramesh, K.; Juan, Joon Ching

    2018-01-01

    A series of novel poly(acrylic acid)-based polymer electrolytes with high conductivities at room temperature has been prepared and studied. Polymer electrolytes composed of poly(acrylic acid) (PAA) and lithium tetrafluoroborate (LiBF4) were prepared by means of solution casting. The effect of the addition of LiBF4 on the properties of the PAA-based electrolyte matrices was analysed and investigated using impedance spectroscopy. The optimized PAA-based solid electrolyte showed an electrochemical stability window of 3.2 V. Thermogravimetric analysis indicated that the incorporation of LiBF4 into PAA matrix enhances the thermal stability. The structural properties of polymer electrolytes were studied by using X-ray diffraction analysis.

  4. Synthesis, characterization, and swelling behaviors of salt-sensitive maize bran-poly(acrylic acid) superabsorbent hydrogel.

    Science.gov (United States)

    Zhang, Mingyue; Cheng, Zhiqiang; Zhao, Tianqi; Liu, Mengzhu; Hu, Meijuan; Li, Junfeng

    2014-09-03

    A novel composite hydrogel was prepared via UV irradiation copolymerization of acrylic acid and maize bran (MB) in the presence of composite initiator (2,2-dimethoxy-2-phenylacetophenone and ammonium persulfate) and cross-linker (N,N'-methylenebis(acrylamide)). Under the optimized conditions, maize bran-poly(acrylic acid) was obtained (2507 g g(-1) in distilled water and 658 g g(-1) in 0.9 wt % NaCl solution). Effects of granularity, salt concentration, and various cations and anions on water absorbency were investigated. It was found that swelling was extremely sensitive to the ionic strength and cation and anion type. Swelling kinetics and water diffusion mechanism in distilled water were also discussed. Moreover, the product showed excellent water retention capability under the condition of high temperature or high pressure. The salt sensitivity, good water absorbency, and excellent water retention capability of the hydrogels give this intelligentized polymer wide potential applications.

  5. Removal of dorzolamide from biomedical wastewaters with adsorption onto graphite oxide/poly(acrylic acid) grafted chitosan nanocomposite.

    Science.gov (United States)

    Kyzas, George Z; Bikiaris, Dimitrios N; Seredych, Mykola; Bandosz, Teresa J; Deliyanni, Eleni A

    2014-01-01

    A novel graphite oxide/poly(acrylic acid) grafted chitosan nanocomposite (GO/CSA) was prepared and used as biosorbent for the removal of pharmaceutical compound (dorzolamide) from biomedical synthetic wastewaters. The performance was evaluated taking into account pH, kinetics and thermodynamics of adsorption. GO/CSA presented higher adsorption capacity in comparison with the parent materials (graphite oxide and poly(acrylic acid) grafted chitosan). All adsorbents prepared were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and potentiometric titration. The surface features were also evaluated after the dorzolamide adsorption in order to derive the adsorption mechanism. It was suggested that the reactive groups of GO and CSA can interact with the amino groups of dorzolamide and mainly the abundance of carboxyl groups of GO/CSA composite was the main reason for its enhanced adsorption capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Effect of ethylene glycol dimethacrylate on swelling and on metformin hydrochloride release behavior of chemically crosslinked pH-sensitive acrylic acid-polyvinyl alcohol hydrogel

    National Research Council Canada - National Science Library

    Akhtar, Muhammad Faheem; Ranjha, Nazar Muhammad; Hanif, Muhammad

    2015-01-01

    The present work objective was to prepare and to observe the effect of ethylene glycol dimethacrylate on swelling and on drug release behavior of pH-sensitive acrylic acid-polyvinyl alcohol hydrogel...

  7. The influence of poly(acrylic) acid number average molecular weight and concentration in solution on the compressive fracture strength and modulus of a glass-ionomer restorative.

    LENUS (Irish Health Repository)

    Dowling, Adam H

    2011-06-01

    The aim was to investigate the influence of number average molecular weight and concentration of the poly(acrylic) acid (PAA) liquid constituent of a GI restorative on the compressive fracture strength (σ) and modulus (E).

  8. Enantiomeric Excess Determination without Chiral Auxiliary Compounds. A New 31P NMR Method for Amino Acid Esters and Primary Amines

    NARCIS (Netherlands)

    Strijtveen, Bert; Kellogg, Richard M.; Feringa, Bernard

    1986-01-01

    Amino acid esters and primary amines yield diastereoisomeric methylphosphonic diamides 5 upon reaction with MePSCl2. The enantiomeric excess of amino acid esters and amines is easily determined by measurement of the ratio of diastereoisomers of 5 by 31P NMR spectroscopy.

  9. Structural Parameters and Swelling Behavior of pH Sensitive Poly(acrylamide-co-acrylic acid) Hydrogels

    OpenAIRE

    Thakur, A.; Wanchoo, R. K.; Singh, P

    2011-01-01

    In the present work, hydrogels based on acrylamide (AAm) and acrylic acid (AAc), crosslinked with N,N’-methylenebisacrylamide (MBAAm) were prepared by free radical polymerization in solution. The effect of initial AAm/AAc mole ratio and nominal crosslinking ratio (moles of crosslinking agent/moles of polymer repeat unit) on the dynamic and equilibrium swelling behaviour of hydrogels was investigated. Hydrogels were characterized by the polymer volume fraction in the swollen state (ν2,s ), the...

  10. A stencil printed, high energy density silver oxide battery using a novel photopolymerizable poly(acrylic acid) separator.

    Science.gov (United States)

    Braam, Kyle; Subramanian, Vivek

    2015-01-27

    A novel photopolymerized poly(acrylic acid) separator is demonstrated in a printed, high-energy-density silver oxide battery. The printed battery demonstrates a high capacity of 5.4 mA h cm(-2) at a discharge current density of 2.75 mA cm(-2) (C/2 rate) while delivering good mechanical flexibility and robustness. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Biodegradable Plastics From a Mixture of Low Density Polyethylene (Ldpe) and Cassava Starch with the Addition of Acrylic Acid

    OpenAIRE

    Susilawati, Susilawati; Mustafa, Irfan; Maulina, Desy

    2011-01-01

    A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% ) was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w) while tensile strength equal to 0,38 Kgf/mm2. SEM characterization showed that biodegradation has occurred by f...

  12. Nanopatterned polystyrene-b-poly(acrylic acid) surfaces to modulate cell-material interaction.

    Science.gov (United States)

    Lizundia, Erlantz; Sáenz-Pérez, Míriam; Patrocinio, David; Aurrekoetxea, Iskander; dM Vivanco, Maria; Vilas, José Luis

    2017-06-01

    In this work we explore the effect of surface nanoarchitecture of polystyrene (PS) and polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymer films on cell viability. PS and PS-b-PAA have been nanopatterned at temperatures of 110, 120 and 140°C using nanoporous aluminium oxide membranes (AAO) as a template. Surface architecture strongly depends on the infiltration temperature and the nature of the infiltrated polymer. High patterning temperatures yield hollow fibre shape architecture at the nanoscale level, which substantially modifies the surface hydrophobicity of the resulting materials. Up to date very scarce reports could be found in the literature dealing with the interaction of microstructured/nanostructured polymeric surfaces with cancer cells. Therefore, MCF-7 breast cancer cells have been selected as a model to conduct cell viability assays. The findings reveal that the fine-tuning of the surface nanoarchitecture contributes to the modification of its biocompatibility. Overall, this study highlights the potential of AAO membranes to obtain well-defined tailored morphologies at nanoscale level and its importance to develop novel soft functional surfaces to be used in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Science.gov (United States)

    Liu, Lei; Luo, Shi-Zhong; Wang, Bin; Guo, ZhanHu

    2015-08-01

    The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (MW 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption-desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  14. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU

    2015-12-01

    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  15. Mechanical, thermal and morphological properties of poly(lactic acid)/ethylene-butyl acrylate copolymer nanocomposites

    Science.gov (United States)

    Wacharawichanant, S.; Hoysang, P.; Ratchawong, S.

    2017-07-01

    This paper reports a melt blend of poly(lactic acid) (PLA)/ethylene-butyl acrylate copolymer (EBAC) with organoclay content at 3 phr. The mechanical, thermal and morphological properties of PLA/EBAC blends and nanocomposites were investigated. The morphological analysis revealed EBAC phase dispersed as a spherical domain in PLA matrix and the domain size of EBAC dispersed phase increased with increasing EBAC content. The addition of organoclay could improve the miscibility of PLA/EBAC blends due to the decrease of domain size of EBAC dispersed phase. The mechanical properties indicated that the strain at break and impact strength of PLA increased when added EBAC, but Young’s modulus and tensile strength decreased. Storage modulus increased with the addition of organoclay to the PLA/EBAC blends. The thermal properties found that the incorporation of organoclay in the PLA/EBAC blends did not effect on the glass transition temperature and melting temperature values relative to PLA. The degradation temperature of PLA improved with the addition of EBAC. This indicated that EBAC has more thermal stability and degradation temperature than PLA. From X-ray diffraction patterns displayed the characteristic peak in PLA/EBAC/organoclay nanocomposites appeared at the lower angle, which indicated the dispersed clay is intercalated in the polymer matrix. However, second-order diffraction peak appeared at the higher angle indicated that there was partially the conventional composite.

  16. Preparation and properties of poly(acrylic acid) oligomer stabilized superparamagnetic ferrofluid.

    Science.gov (United States)

    Lin, Chia-Lung; Lee, Chia-Fen; Chiu, Wen-Yen

    2005-11-15

    Ferrofluids, which are stable dispersions of magnetic particles, behave as liquids that have strong magnetic properties. Nanoparticles of magnetite with a mean diameter of 10-15 nm, which are in the range of superparamagnetism, are usually prepared by the traditional method of co-precipitation from ferrous and ferric electrolyte solution. When diluted, the ferrofluid dispersions are not stable if anionic or cationic surfactants are used as the stabilizer. This work presents an efficient way to prepare a stable aqueous nanomagnetite dispersion. A stable ferrofluid containing Fe3O4 nanoparticles was synthesized via co-precipitation in the presence of poly(acrylic acid) oligomer. The mechanism, microstructure, and properties of the ferrofluid were investigated. The results indicate that the PAA oligomers promoted the nucleation and inhibited the growth of the magnetic iron oxide, and the average diameter of each individual Fe3O4 particle was smaller than 10 nm. In addition, the PAA oligomers provided both electrostatic and steric repulsion against particle aggregation, and the stability of dispersions could be controlled by adjusting the pH value of solution. A small amount of Fe2O3 was found in the nanoparticles but the superparamagnetic behavior of the nanoparticles was not affected.

  17. Sustained release gastroretentive tablet of metformin hydrochloride based on poly (acrylic acid)-grafted-gellan.

    Science.gov (United States)

    Sarkar, Debjani; Nandi, Gouranga; Changder, Abhijit; Hudati, Prasenjit; Sarkar, Sayani; Ghosh, Lakshmi Kanta

    2017-03-01

    Development of a gastroretentive sustained release tablet of metformin based on poly (acrylic acid)-grafted-gellan (PAAc-g-GG) is the main purpose of this study. At first, PAAc-g-GG was synthesized by microwave-promoted free radical initiation method using cerric (IV) ammonium nitrate (CAN) as redox initiator and characterized by elemental analysis, FTIR, DSC-TGA, (13)C NMR, biodegradation and viscosity study. The synthetic parameters were optimized by 2(3) full factorial design using Design Expert software. Acute oral toxicity and histological studies were also performed as per OECD guideline. Tablets were then prepared employing wet granulation method using PAAc-g-GG and evaluated for various physical characters, in vitro drug release, ex-vivo mucoadhesion and swelling. Compatibility between drug and excipients was checked by DSC and FTIR analysis. The F3 batch showed excellent mucoadhesion and sustained drug release over a period of 10h with dissolution similarity factor, f2=77.43. Kinetic modeling unveiled Case-1 Fickian diffusion based drug release mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Properties of copper micropowders electroplated from sulfate solutions with acrylic acid or acrylamide

    Directory of Open Access Journals (Sweden)

    Viktor F. Vargalyuk

    2014-03-01

    Full Text Available Based on the results of X-ray diffraction analysis it has been ascertained that cathodic copper deposit precipitated from sulfate electrolyte with acrylic acid or acrylamide consist of copper crystals with considerable quantity of imperfections and crystal deformations. It has been revealed that microstress and dislocation density in the deposits increase with enhancement of organic component concentration in the solution according to symbasis dependences. Decreasing of crystallite size and increasing of structuring degree for the deposits has been observed. Peaks of any phases except copper have not been identified on X-ray diffraction pattern of the deposits. In earlier investigation it has been shown that nonmetallic component (copper π-complexes makes up 20% of the deposits. So based on the results of X-ray diffraction investigations we can conclude that the deposit consist of copper micro crystals separated by nonmetallic component. Owing to special physical-mechanical properties of the deposits it became possible to transform them to superfine powder by means of mechanical fragmentation. Using sedimentation and microscopic analysis it has been shown that cathodic micro powders precipitated from solutions with organic compounds are homogeneous by form and dimension. Significant bactericidal and bacteriostatic effects of cathodic micro powders influence have been detected.

  19. Improved biotribological properties of PEEK by photo-induced graft polymerization of acrylic acid.

    Science.gov (United States)

    Zhao, Xiaoduo; Xiong, Dangsheng; Wang, Kun; Wang, Nan

    2017-06-01

    The keys of biomaterials application in artificial joints are good hydrophilicity and wear resistance. One kind of the potential bio-implant materials is polyetheretherketone (PEEK), which has some excellent properties such as non-toxic and good biocompatibility. However, its bioinert surface and inherent chemical inertness hinder its application. In this study, we reported an efficient method for improving the surface wettability and wear resistance for PEEK, a layer of acrylic acid (AA) polymer brushes on PEEK surface was prepared by UV-initiated graft polymerization. The effects of different grafting parameters (UV-irradiation time/AA monomer solution concentration) on surface characteristics were clearly investigated, and the AA-g-PEEK specimens were examined by ATR-FTIR, static water contact angle measurements and friction tests. Our results reveal that AA can be successfully grafted onto the PEEK surface after UV irradiation, the water wettability and tribological properties of AA-g-PEEK are much better than untreated PEEK because that AA is a hydrophilic monomer, the AA layer on PEEK surface can improve its bearing capacity and reduce abrasion. This detailed understanding of the grafting parameters allows us to accurately control the experimental products, and this method of surface modification broadens the use of PEEK in orthopedic implants. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Polyelectrolyte Complex Nanoparticles of Poly(ethyleneimine and Poly(acrylic acid: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Martin Müller

    2011-04-01

    Full Text Available In this contribution we outline polyelectrolyte (PEL complex (PEC nanoparticles, prepared by mixing solutions of the low cost PEL components poly(ethyleneimine (PEI and poly(acrylic acid (PAC. It was found, that the size and internal structure of PEI/PAC particles can be regulated by process, media and structural parameters. Especially, mixing order, mixing ratio, PEL concentration, pH and molecular weight, were found to be sensible parameters to regulate the size (diameter of spherical PEI/PAC nanoparticles, in the range between 80–1,000 nm, in a defined way. Finally, applications of dispersed PEI/PAC particles as additives for the paper making process, as well as for drug delivery, are outlined. PEI/PAC nanoparticles mixed directly on model cellulose film showed a higher adsorption level applying the mixing order 1. PAC 2. PEI compared to 1. PEI 2. PAC. Surface bound PEI/PAC nanoparticles were found to release a model drug compound and to stay immobilized due to the contact with the aqueous release medium.

  1. Osmotic Engine: Translating Osmotic Pressure into Macroscopic Mechanical Force via Poly(Acrylic Acid) Based Hydrogels

    Science.gov (United States)

    Arens, Lukas; Weißenfeld, Felix; Klein, Christopher O.; Schlag, Karin

    2017-01-01

    Poly(acrylic acid)‐based hydrogels can swell up to 100–1000 times their own weight in desalinated water due to osmotic forces. As the swelling is about a factor of 2–12 lower in seawater‐like saline solutions (4.3 wt% NaCl) than in deionized water, cyclic swelling, and shrinking can potentially be used to move a piston in an osmotic motor. Consequently, chemical energy is translated into mechanical energy. This conversion is driven by differences in chemical potential and by changes in entropy. This is special, as most thermodynamic engines rely instead on the conversion of heat into mechanical energy. To optimize the efficiency of this process, the degree of neutralization, the degree of crosslinking, and the particle size of the hydrogels are varied. Additionally, different osmotic engine prototypes are constructed. The maximum mean power of 0.23 W kg−1 dry hydrogel is found by using an external load of 6 kPa, a polymer with 1.7 mol% crosslinking, a degree of neutralization of 10 mol%, and a particle size of 370–670 µm. As this is achieved only in the first round of optimization, higher values of the maximum power average over one cycle seem realistic. PMID:28932675

  2. Multiplex Immunoassay Platforms Based on Shape-Coded Poly(ethylene glycol) Hydrogel Microparticles Incorporating Acrylic Acid

    Science.gov (United States)

    Park, Saemi; Lee, Hyun Jong; Koh, Won-Gun

    2012-01-01

    A suspension protein microarray was developed using shape-coded poly(ethylene glycol) (PEG) hydrogel microparticles for potential applications in multiplex and high-throughput immunoassays. A simple photopatterning process produced various shapes of hydrogel micropatterns that were weakly bound to poly(dimethylsiloxane) (PDMS)-coated substrates. These micropatterns were easily detached from substrates during the washing process and were collected as non-spherical microparticles. Acrylic acids were incorporated into hydrogels, which could covalently immobilize proteins onto their surfaces due to the presence of carboxyl groups. The amount of immobilized protein increased with the amount of acrylic acid due to more available carboxyl groups. Saturation was reached at 25% v/v of acrylic acid. Immunoassays with IgG and IgM immobilized onto hydrogel microparticles were successfully performed with a linear concentration range from 0 to 500 ng/mL of anti-IgG and anti-IgM, respectively. Finally, a mixture of two different shapes of hydrogel microparticles immobilizing IgG (circle) and IgM (square) was prepared and it was demonstrated that simultaneous detection of two different target proteins was possible without cross-talk using same fluorescence indicator because each immunoassay was easily identified by the shapes of hydrogel microparticles. PMID:22969408

  3. Preparation and electro-response of chitosan-g-poly (acrylic acid) hydrogel elastomers with interpenetrating network

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianli [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Gao, Ling-xiang, E-mail: gaolx@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Han, Xuewu; Chen, Tao; Luo, Jue; Liu, Kaiqiang; Gao, Ziwei; Zhang, Weiqiang [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China)

    2016-02-01

    In this article, novel chitosan-g-poly (acrylic acid) hydrogel elastomers were successfully sythesised by grafting chitosan (CTS) onto poly acrylic acid (PAA) through radical polymerization in the presence/absence of direct current electric field. Their structure and electro-response were evaluated through scanning electron microscopy (SEM), infrared spectroscopy (IR), and dynamic mechanical analyser (DMA), respectively. Stress-strain test showed that the toughness of the chitosan-g-PAA elastomer is higher than the PAA gel. The result demonstrates the elastomers obtained in the presence/absence of electric field with similar chemical composition possess different microstructure. The positive electro responsive effect appeared on the elastomers, and both of storage modulus increment and increment sensitivity yielded maximum value at the AA concentration of 14.09 wt% under the applied electric field of 1.5 kV/mm. Thermo gravimetry and differential scanning calorimetry (TG-DSC) showed the elastomers cured under an applied electric field have stronger intramolecular bonding and higher cross-linking density. - Highlights: • The chitosan-g-poly (acrylic acid) hydrogel elastomers have been prepared. • They have ordered structure and positive electro-response under an electric field. • The maximum electro-response occurs near or at the AA wt% of 14.09 under 1.5 kV/mm.

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

    Science.gov (United States)

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

    2014-02-15

    Methionol-derived fatty acid esters were synthesised by both chemical and lipase catalysed esterification between fatty acids and methionol. Beneficial effects of both methods were compared qualitatively and quantitatively by GC-MS/GC-FID results. And the high acid and heat stability of our designed methionyl esters meet the requirement of the food industry. Most importantly, the sensory test showed that fatty acid carbon-chain length had an important effect on the flavour attributes of methionyl esters. Moreover, through Lipozyme TL IM-mediated transesterification, valuable methionol-derived esters were synthesised from the readily available natural material butter oil as the fatty acid source. The conversion of methionol and yield of each methionyl ester were also elucidated by GC-MS-FID. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. N-Cholyl Amino Acid Alkyl Esters - A Novel Class of Organogelators

    NARCIS (Netherlands)

    Willemen, H.M.; Vermonden, T.; Marcelis, A.T.M.; Sudhölter, E.J.R.

    2001-01-01

    Several N-cholyl amino acid alkyl esters were found to act as novel, potent organogelators for aromatic solvents and cyclohexene. These novel organogelators afford stable, transparent, and thermoreversible gels. Modification of the molecular structure and IR measurements show that gelation takes

  6. Low-temperature side-chain cleavage and decarboxylation of polythiophene esters by acid catalysis

    DEFF Research Database (Denmark)

    Søndergaard, Roar; Norrman, Kion; Krebs, Frederik C

    2012-01-01

    substituents have been examined by TGA‐MS using different sulphonic acids. A substantial lowering of the cleavage temperature is observed, and the ester cleavage can even be performed in situ on roll‐to‐roll‐coated films on polyethylene terephthalate (PET). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A...

  7. Developmental toxicity study of vegetable oil-derived stanol fatty acid esters

    NARCIS (Netherlands)

    Slesinski, R.S.; Turnbull, D.; Frankos, V.H.; Wolterbeek, A.P.M.; Waalkens-Berendsen, D.H.

    1999-01-01

    In a standard developmental toxicity study, a mixture of vegetable oil- derived stanol fatty acid esters was administered in the diet to groups of 28 mated female HsdCpb:WU Wistar rats at concentrations that provided 0, 1, 2.5, and 5% total stanols (equivalent to 0, 1.75, 4.38, and 8.76% plant

  8. Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator

    NARCIS (Netherlands)

    Ilmi, Miftahul; Abduh, Muhammad Yusuf; Hommes, Arne; Winkelman, Jozef; Hidayat, C.; Heeres, Hero

    2018-01-01

    Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous

  9. Influence of Fatty Acid Methyl Esters on Fuel properties of Biodiesel ...

    African Journals Online (AJOL)

    Oil extracted from the seeds of Curcubita pepo was transesterified using potassium hydroxide in methanol. Fatty acid methyl esters (FAME) profile of the produced diesel was analyzed using Gas chromatograph coupled with mass spectrophotometer (GC-MS). The results indicate the presence of methyl ...

  10. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene oxide...

  11. CFD simulation of fatty acid methyl ester production in bubble column reactor

    Science.gov (United States)

    Salleh, N. S. Mohd; Nasir, N. F.

    2017-09-01

    Non-catalytic transesterification is one of the method that was used to produce the fatty acid methyl ester (FAME) by blowing superheated methanol bubbles continuously into the vegetable oil without using any catalyst. This research aimed to simulate the production of FAME from palm oil in a bubble column reactor. Computational Fluid Dynamic (CFD) simulation was used to predict the distribution of fatty acid methyl ester and other product in the reactor. The fluid flow and component of concentration along the reaction time was investigated and the effects of reaction temperature (523 K and 563 K) on the non-catalytic transesterification process has been examined. The study was carried out using ANSYS CFX 17.1. The finding from the study shows that increasing the temperature leads to higher amount of fatty acid methyl ester can be produced in shorter time. On the other hand, concentration of the component such as triglyceride (TG), glycerol (GL) and fatty acid methyl ester (FAME) can be known when reaching the optimum condition.

  12. 40 CFR 721.6475 - Alkyl polycarboxylic acids, esters with ethoxylated fatty alcohols.

    Science.gov (United States)

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES... chemical substances identified generically as alkyl polycarboxylic acids, esters with ethoxylated fatty... requirements. The provisions of subpart A of this part apply to this section except as modified by this...

  13. 4-[(2-Hydroxy-4-pentadecyl-benzylidene-amino]-benzoic Acid Methyl Ester

    Directory of Open Access Journals (Sweden)

    Gadada Naganagowda

    2013-11-01

    Full Text Available A new Schiff base, 4-[(2-hydroxy-4-pentadecyl-benzylidene-amino]-benzoic acid methyl ester was synthesized and its UV, IR, 1H-NMR, 13C-NMR and ESI-MS spectroscopic data are presented.

  14. Carbohydrate fatty acid monosulphate esters are safe and effective adjuvants for humoral responses

    NARCIS (Netherlands)

    Hilgers, L.A.T.; Platenburg, P.; Bajramovic, J.; Veth, J.; Sauerwein, R.; Roeffen, W.; Pohl, M.; Amerongen, G. van; Stittelaar, K.J.; Bosch, J.F. van den

    2017-01-01

    Carbohydrate fatty acid sulphate esters (CFASEs) formulated in a squalane-in-water emulsion are effective adjuvants for humoral responses to a wide range of antigens in various animal species but rise in body temperature and local reactions albeit mild or minimal hampers application in humans. In

  15. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: A case series

    NARCIS (Netherlands)

    D.M.W. Balak (Deepak); J.N.B. Bavinck (Jan Nico Bouwes); De Vries, A.P.J. (Aiko P. J.); Hartman, J. (Jenny); Martino Neumann, H.A. (Hendrik A.); R. Zietse (Bob); H.B. Thio (Bing)

    2016-01-01

    textabstractBackground: Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced

  16. Fumaric acid esters in recalcitrant pediatric psoriasis: A prospective, daily clinical practice case series

    NARCIS (Netherlands)

    Geel, M.J. van; Kerkhof, P.C. van de; Oostveen, A.M.; Jong, E.M. de; Seyger, M.M.

    2016-01-01

    BACKGROUND: Evidence on fumaric acid esters (FAE) in the treatment of pediatric psoriasis is scarce. OBJECTIVE: Describe the effectiveness, influence on the quality of life (QoL) and safety of FAE in children with recalcitrant psoriasis in daily clinical practice. METHODS: A prospective case series.

  17. Regulated genes in psoriatic skin during treatment with fumaric acid esters

    NARCIS (Netherlands)

    Onderdijk, A. J.; Balak, D. M. W.; Baerveldt, E. M.; Florencia, E. F.; Kant, M.; Laman, J. D.; van IJcken, W. F. . J.; Racz, E.; de Ridder, D.; Thio, H. B.; Prens, E. P.

    2014-01-01

    BackgroundFumaric acid esters (FAEs) are widely used in Europe for the treatment of psoriasis because of their clinical efficacy and favourable safety profile. However, the mechanisms of action by which FAEs improve psoriasis remain largely unknown. ObjectivesTo identify pathways and mechanisms

  18. Chemical modification of nanocellulose with canola oil fatty acid methyl ester

    Science.gov (United States)

    Liqing Wei; Umesh P. Agarwal; Kolby C. Hirth; Laurent M. Matuana; Ronald C. Sabo; Nicole M. Stark

    2017-01-01

    Cellulose nanocrystals (CNCs), produced from dissolving wood pulp, were chemically functionalized by transesterification with canola oil fatty acid methyl ester (CME). CME performs as both the reaction reagent and solvent. Transesterified CNC (CNCFE) was characterized for their chemical structure, morphology, crystalline structure, thermal stability, and hydrophobicity...

  19. Preparation and Structural Analysis of Nano-Silver Loaded Poly(styrene-co-acrylic acid) Core-Shell Nanospheres with Defined Shape and Composition.

    Science.gov (United States)

    Zhang, Jin; Zhao, Xiaoyu; Wang, Yanfei; Zhu, Liang; Yang, Libin; Li, Gang; Sha, Zuoliang

    2017-08-23

    A systematic study for the preparation and structural analysis of poly(styrene- co -acrylic acid) composite nanospheres (PSA) and silver nanoparticles loaded poly(styrene- co -acrylic acid) composite nanospheres (nAg@PSA) is reported. Poly(styrene- co -acrylic acid) nanospheres were synthesized by soap-free emulsion polymerization of styrene (St) and acrylic acid (AA) in water. Ag nanoparticles (Ag-NPs) were well-dispersed on the surfaces of poly(styrene- co -acrylic acid) composite nanospheres by in situ chemical reduction of AgNO₃ using NaBH₄ as a reducing agent in water. The particle size of PSA nanospheres was uniform. The surfaces of PSA nanospheres were distributed by highly uniform half-sphere arrays. Those half-sphere protruded more with the increase of the feeding amount of AA or the feed ratios of AA and St. The carboxyl groups content of nanospheres was directly proportional to the nanosphere surface area. This relationship and X-ray photoelectron spectroscopy and transmission electron microscopy images of the PSA nanospheres indicate that the acrylic acid was mainly distributed on the surface of the polystyrene spheres with unnegligible thickness. The number of Ag-NPs depends on immobilized carboxyl groups on the surface of PSA, according to thermogravimetry, ultraviolet-visible, X-ray diffraction and transmission electron microscopy results.

  20. Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae).

    Science.gov (United States)

    Zheoat, Ahmed M; Gray, Alexander I; Igoli, John O; Kennedy, Alan R; Ferro, Valerie A

    2017-09-01

    The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2S,3R)-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carb-oxy-lic acid dimethyl sulfoxide monosolvate], C6H6O7·C2H6OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2S,3R)-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carboxyl-ate], C8H10O7, (II). Compound (I) forms a layered structure with alternating layers of lactone and solvent mol-ecules, that include a two-dimensional hydrogen-bonding construct. Compound (II) has two crystallographically independent and conformationally similar mol-ecules per asymmetric unit and forms a one-dimensional hydrogen-bonding construct. The known absolute configuration for both compounds has been confirmed.

  1. Potentiation of insulin release in response to amino acid methyl esters correlates to activation of islet glutamate dehydrogenase activity

    DEFF Research Database (Denmark)

    Kofod, Hans; Lernmark, A; Hedeskov, C J

    1986-01-01

    Column perifusion of mouse pancreatic islets was used to study the ability of amino acids and their methyl esters to influence insulin release and activate islet glutamate dehydrogenase activity. In the absence of L-glutamine, L-serine and the methyl ester of L-phenylalanine, but neither L...... glutamate dehydrogenase activity showed that only the two methyl esters of L-phenylalanine and L-serine activated the enzyme. It is concluded that the mechanism by which methyl esters of amino acids potentiate insulin release is most likely to be mediated by the activation of pancreatic beta-cell glutamate...

  2. Synthesis and transdermal properties of acetylsalicylic acid and selected esters

    OpenAIRE

    Gerber, Minja; Breytenbach, Jaco C.; Hadgraft, Jonathan; du Plessis, Jeanetta

    2006-01-01

    The primary aim of this study was to determine the transdermal penetration of acetylsalicylic acid and some of its derivatives, to establish a correlation, if any, with selected physicochemical properties and to determine if transdermal application of acetylsalicylic acid and its derivatives will give therapeutic drug concentrations with respect to transdermal flux. Ten derivatives of acetylsalicylic acid were prepared by esterification of acetylsalicyloyl chloride with ten different alcohols...

  3. Sodium Carboxymethyl Cellulose Using Acrylamide and Acrylic Acid and Investigation of Drug Delivery Properties

    Directory of Open Access Journals (Sweden)

    Mahdi Geramipour

    2016-07-01

    Full Text Available Hydrogels are three-dimensional polymer networks that can absorb and retain a huge amount of aqueous fluids even under certain pressure, but do not dissolve in water. They are responsive to environmental stimulants such as pH and ionic strength of the solution. In this study, a series of novel sodium carboxymethyl cellulose-based hydrogel nanocomposites were synthesized using acrylamide comonomer in the presence of iron magnetic as crosslinker and acrylic acid ammonium persulfate (APS comonomer as initiator. All reaction variables affecting the water absorbency of the hydrogel nanocomposite including the concentration of crosslinking agent and initiator, and comonomers ratio were optimized in order to achieve the maximum absorption capacity. The experimental data showed that the hydrogel nanocomposite exhibited improved swelling capacity compared to the nanoparticel-free hydrogel. In addition, optimized hydrogel nanocomposite showed a good water uptake ability and the equilibrium swelling capacity was achieved within the initial 10 min. In examining the quality of the synthesized hydrogel nanocomposite, the amount of absorption in saline solutions of different concentrations was measured. Furthermore, the swelling behavior of hydrogel nanocomposite in solutions with different pH values was evaluated. The chemical structure of the hydrogel nanocomposites was characterized by means of transmission electron microscopy (TEM, scanning electron microscopy (SEM, vibrating sample magnetometry (VSM, thermogravimetry analysis (TGA, derivative thermogravimetry (DTG and Fourier transform infrared spectroscopy (FTIR. In order to study the drug delivery and drug release behavior, the release of sodium diclofenac as a model drug from synthesized hydrogel nanocomposite was examined in two acidic and basic buffer environments. The results indicated that this hydrogel nanocomposite may be an appropriate alternative for drug release processes in human body.

  4. Asymmetric Meerwein–Ponndorf–Verley reduction of long chain keto alkanoic acid methyl esters

    Directory of Open Access Journals (Sweden)

    AYE YUSUFOGLU

    2007-05-01

    Full Text Available 3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a ketogroup at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein–Ponndorf–Verley reaction in the presence of R-(+-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(–-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1H-NMR shift with Eu(tfc3 and by optical rotation.

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

    Directory of Open Access Journals (Sweden)

    Ion Dragalin

    2015-12-01

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

  6. Synthesis and swelling property of superabsorbent starch grafted with acrylic acid/2-acrylamido-2-methyl-1-propanesulfonic acid.

    Science.gov (United States)

    Meng, Yeqiao; Ye, Lin

    2017-08-01

    In order to develop starch-based superabsorbent polymers (SAPs) with high water absorbency, both acrylic acid (AA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) were graft copolymerized onto cassava starch, and St-g-AA-AMPS SAP was successfully synthesized. The effect of AA/AMPS molar ratio on the structure and swelling property of SAP was investigated. Introduction of AMPS units improved the storage modulus and crosslinking density of St-g-AA-AMPS SAP, and was beneficial in forming a perfect network structure. With increasing AMPS content, the equilibrium swelling ratio and swelling rate constant (k) of the SAP first increased and then decreased, and the maximum swelling ratio reached 1200.0 and 90.0 g/g in distilled water and brine respectively, resulting from the high ionization constant and hydrophilic ability of AMPS, and improved tolerance to brine. By introducing AMPS units, the re-swelling capability of SAP was improved, and more hydrogen bonds could form between molecules of water and SAP, leading to an increase in non-freezing bound water and freezing bound water, and the water retention of SAP was enhanced. Introduction of AMPS units improved the water absorption capacity, swelling rate, and water retention ability of St-g-AA-AMPS SAP, presenting wide application potential in agriculture and horticulture of desert regions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Secreted 3-isopropylmalate methyl ester signals invasive growth during amino acid starvation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Dumlao, Darren S; Hertz, Nicholas; Clarke, Steven

    2008-01-15

    The Saccharomyces cerevisiae methyltransferase encoded by TMT1 catalyzes the AdoMet-dependent monomethylation of 3-isopropylmalate, an intermediate of the leucine biosynthetic pathway. The biological significance of methylating 3-isopropylmalate and the relationship between Tmt1 and the leucine biosynthetic pathway is not yet established. We present evidence here showing that methylation of 3-isopropylmalate functions to extracellularly signal yeast to grow invasively. We show that methyl esterification generates 3-isopropylmalate-1-methyl ester. We find that the Tmt1 methyltransferase functions independently of the biosynthetic pathway but is induced when cells are starved for amino acids; the largest induction is observed with the removal of leucine from the media. This amino acid starvation stress response is controlled by the transcriptional activator Gcn4. After methylation, 3-isopropylmalate methyl ester is secreted into the media within 3 h. Thin layer chromatography and gas chromatography mass spectroscopy confirm that the intact molecule is secreted. Finally, we show that purified 3-isopropylmalate methyl ester can enhance the ability of the haploid yeast strain 10560-23C to grow invasively. Our data identifies 3-isopropylmalate methyl ester as an autoinductive molecule that provides a signal to yeast to switch from vegetative to invasive growth in response to amino acid starvation.

  8. Biosynthesis of the fatty acid isopropyl esters by engineered Escherichia coli.

    Science.gov (United States)

    Pan, Hong; Zhang, Lihua; Li, Xun; Guo, Daoyi

    2017-07-01

    The fatty acid methyl esters and fatty acid ethyl esters are known as biodiesels which are considered to be renewable, nontoxic and biodegradable biofuels. However, the conventional biodiesels show a high crystallization temperature which is one of the most critical obstacles against the widespread biodiesel usage. The high crystallization temperature of biodiesel can be reduced by replacing the methyl or ethyl ester with an isopropyl moiety. Here we report on a strategy to establish biosynthesis of the fatty acid isopropyl esters(FAIPEs) from the simple substrate glucose in Escherichia coli with heterologous coexpression of atoB encoded acetyl-CoA acetyltransferase and atoAD encode acetoacetyl-CoA transferase from E. coli, ADC encode acetoacetate decarboxylase from Clostridium acetobutylicum, ADH encoded NADP-dependent alcohol dehydrogenase from Clostridium beijerinckii, 'TesA encoded a truncated fatty acyl-ACP thioesterase and FadD encoded fatty acyl-CoA synthetase from E. coli, and the WS/DGAT encoded acyltransferase from Acinetobacter baylyi strain ADP1. It was found that the yield of FAIPEs was up to 203.4mg/L and accounted for around 6.4% (wt/wt) of the dry cell weight. Our results indicates that it is a feasible strategy to improve the yield of FAIPEs by increasing fatty acyl-CoA availability in biosynthetic pathway and exhibit a promising method for production of biodiesels with good low-temperature flow properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Synthesis and transdermal properties of acetylsalicylic acid and selected esters.

    Science.gov (United States)

    Gerber, Minja; Breytenbach, Jaco C; Hadgraft, Jonathan; du Plessis, Jeanetta

    2006-03-09

    The primary aim of this study was to determine the transdermal penetration of acetylsalicylic acid and some of its derivatives, to establish a correlation, if any, with selected physicochemical properties and to determine if transdermal application of acetylsalicylic acid and its derivatives will give therapeutic drug concentrations with respect to transdermal flux. Ten derivatives of acetylsalicylic acid were prepared by esterification of acetylsalicyloyl chloride with ten different alcohols. The experimental aqueous solubility, logD and transdermal flux values were determined for acetylsalicylic acid and its derivatives at pH 4.5. In vitro penetration was measured through excised female human abdominal skin in diffusion cells. The experimental aqueous solubility of acetylsalicylic acid (6.56 mg/ml) was higher than that of the synthesised acetylsalicylate derivatives (ranging from 1.76 x 10(-3) to 3.32 mg/ml), and the logD of acetylsalicylic acid (-0.85) was lower than that of its derivatives (ranging from -0.25 to 1.95). There was thus an inverse correlation between the aqueous solubility data and the logD values. The experimental transdermal flux of acetylsalicylic acid (263.83 nmol/cm(2)h) was much higher than that of its derivatives (ranging from 0.12 to 136.02 nmol/cm(2)h).

  10. Uptake in brain and neurophysiological activity of two lipid esters of gamma-aminobutyric acid.

    Science.gov (United States)

    Hesse, G W; Jacob, J N; Shashoua, V E

    1988-06-01

    Two lipid esters of gamma-aminobutyric acid (GABA), 1-linolenoyl-2,3-bis(4-aminobutyryl)propane-1,2,3-triol and 1,2-dilinolenoyl-3-(4-aminobutyryl)propane-1,2,3-triol, were found to have brain uptake indices of greater than 30% using the single-pass carotid artery injection technique. Both compounds produced dose-dependent inhibition of the evoked population spike in slices of rat hippocampus maintained in vitro. This effect was blocked reversibly by picrotoxin. The magnitude of the inhibition produced by the lipid esters of GABA was comparable to that of similar doses of GABA, but for both compounds the duration of the effect was at least 10 times longer than that produced by GABA. These data are consistent with the idea that the lipid esters of GABA can effectively penetrate the blood-brain barrier and act as prodrugs for the delivery of GABA to the central nervous system.

  11. Enzymatic synthesis of arbutin undecylenic acid ester and its inhibitory effect on mushroom tyrosinase.

    Science.gov (United States)

    Tokiwa, Y; Kitagawa, M; Raku, T

    2007-03-01

    A novel tyrosinase inhibitor, an arbutin derivative having undecylenic acid at the 6-position of its glucose moiety, was enzymatically synthesized. Its inhibitory activity was studied in vitro by using catechol and phenol as substrates. The IC(50) value of the arbutin ester on tyrosinase using catechol (4 x 10(-4) M) was 1% of that when arbutin (4 x 10(-2) M) was used. Using phenol, IC(50) of the arbutin ester (3 x 10(-4) M) as substrate was 10% of that of arbutin (3 x 10(-3) M). These results suggest that the arbutin ester inhibits the latter part of the tyrosinase reaction, which consists of hydroxylation and oxidation.

  12. Physiological and transcriptional characterization of Saccharomyces cerevisiae engineered for production of fatty acid ethyl esters

    DEFF Research Database (Denmark)

    de Jong, Bouke Wim; Siewers, Verena; Nielsen, Jens

    2016-01-01

    Saccharomyces cerevisiae has previously been engineered to become a cell factory for the production of fatty acid ethyl esters (FAEEs), molecules suitable for crude diesel replacement. To find new metabolic engineering targets for the improvement of FAEE cell factories, three different FAEE......-producing strains of S. cerevisiae, constructed previously, were compared and characterized by quantification of key fluxes and genome-wide transcription analysis. From both the physiological and the transcriptional data, it was indicated that strain CB2I20, with high expression of a heterologous wax ester synthase...... gene (ws2) and strain BdJ15, containing disruptions of genes DGA1, LRO1, ARE1, ARE2 and POX1, which prevent the conversion of acyl-CoA to sterol esters, triacylglycerides and the degradation to acetyl-CoA, triggered oxidative stress that consequently influenced cellular growth. In the latter strain...

  13. Optimal Design for Reactivity Ratio Estimation: A Comparison of Techniques for AMPS/Acrylamide and AMPS/Acrylic Acid Copolymerizations

    OpenAIRE

    Scott, Alison J.; Marzieh Riahinezhad; Alexander Penlidis

    2015-01-01

    Water-soluble polymers of acrylamide (AAm) and acrylic acid (AAc) have significant potential in enhanced oil recovery, as well as in other specialty applications. To improve the shear strength of the polymer, a third comonomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), can be added to the pre-polymerization mixture. Copolymerization kinetics of AAm/AAc are well studied, but little is known about the other comonomer pairs (AMPS/AAm and AMPS/AAc). Hence, reactivity ratios for AMPS/AAm ...

  14. Mechanisms and Origins of Selectivities of the Lewis Acid-Catalyzed Diels-Alder Reactions between Arylallenes and Acrylates.

    Science.gov (United States)

    Yu, Peiyuan; Li, Wei; Houk, K N

    2017-06-16

    The mechanisms of recently reported Lewis acid-catalyzed Diels-Alder reactions of arylallenes and acrylates were studied using density functional theory calculations. A stepwise mechanism involving short-lived zwitterion intermediates is established. The reaction is endo-selective in the presence of Lewis acid catalyst. The [2 + 2] cycloaddition is not observed because of the greater charge separation in the first step of the [2 + 2] cycloaddition. The origins of chirality transfer in the Diels-Alder reaction using chiral arylallenes are uncovered, and the absolute stereochemistry of the product is predicted.

  15. Hydroxycinnamic acid ethyl esters as precursors to ethylphenols in wine.

    Science.gov (United States)

    Hixson, Josh L; Sleep, Nicola R; Capone, Dimitra L; Elsey, Gordon M; Curtin, Christopher D; Sefton, Mark A; Taylor, Dennis K

    2012-03-07

    A method for determining ethyl coumarate and ethyl ferulate in wine using GC-MS with deuterium-labeled analogues has been developed and used to measure the evolution of these two esters during the production of two commercial monovarietal red wines, cv. Grenache and Shiraz. During fermentation, the concentration of ethyl coumarate rose from low levels to 0.4 mg/L in Grenache and 1.6 mg/L in Shiraz wines. These concentrations then increased further during barrel aging to 1.4 and 3.6 mg/L, respectively. The concentration of ethyl ferulate was much lower, reaching a maximum of only 0.09 mg/L. Conversion of ethyl coumarate and ethyl ferulate to their corresponding ethylphenols was observed during fermentations of a synthetic medium with two strains of Dekkera bruxellensis (AWRI 1499 and AWRI 1608), while a third (strain AWRI 1613) produced no ethylphenols at all from these precursors. Strains AWRI 1499 and 1608 produced 4-ethylphenol from ethyl coumarate in 68% and 57% yields, respectively. The corresponding yields of 4-ethylguaiacol from ethyl ferulate were much lower, 7% and 3%. Monitoring of ethyl coumarate and ethyl ferulate concentration during the Dekkera fermentations showed that the selectivity for ethylphenol production according to yeast strain and the precursor was principally a result of variation in esterase activity. Consequently, ethyl coumarate can be considered to be a significant precursor to 4-ethylphenol in wines affected by these two strains of Brettanomyces/Dekkera yeast, while ethyl ferulate is not an important precursor to 4-ethylguaiacol.

  16. Parallel Synthesis of an Imidazole-4,5-dicarboxamide Library Bearing Amino Acid Esters and Alkanamines

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2008-12-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters and alkanamines to afford compounds with intramolecularly hydrogen bonded conformations that mimic substituted purines and therefore are hypothesized to be potential inhibitors of kinases through competitive binding to the ATP site. In this work, a total of 126 dissymmetrically disubstituted imidazole-4,5-dicarboxamides with amino acid ester and alkanamide substituents were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by 1H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR for screening in the Molecular Library Screening Center Network (MLSCN as part of the NIH Roadmap.

  17. Fracture Mechanisms of Layer-By-Layer Polyurethane/Poly(Acrylic Acid) Nanocomposite

    Science.gov (United States)

    Kheng, Eugene R.

    A layer-by-layer(LBL) manufactured material is examined in detail in this thesis. Improvements are made to the method of its manufacture. Efforts are made to understand its fracture mechanisms and take advantage of these fracture mechanisms in the absorption of impact energy. A novel series of experiments has been performed on LBL manufactured thin films to demonstrate their unique fracture mechanisms. Polyurethane/Poly(Acrylic Acid) (PU/PAA) and PU/PAA/(PU/Clay)5 nanocomposite films readily undergo Interlaminar mode II fracture, because of the relatively weak elctrostatic bonds between monolayers. Tensile tests performed while under observation by a scanning electron microscope demonstrate the tendency of these nanocomposite films to undergo interlaminar mode II fracture even when loads are applied in the plane of nanocomposite film. It is concluded that these mechanisms of energy dissipation are responsible for the enhanced toughness of these films when used as layers between glass blocks in the prevention of impact damage to the glass. A novel automated manufacturing facility has been designed and built to deposit large sheets of Layer-by-Layer nanocomposite film. These large sheets are incorporated into a borosillicate glass composite in order to compare the ballistic characteristics of LBL PU based nanocomposite films to a single cast layer of polyurethane. It is demonstrated that shear fracture is the mode of failure in the blocks containing the nanocomposite film. The shear fracture surface in the nanocomposite after it has undergone a ballistic impact is characterized. Additional experiments are performed to characterize the interlaminar fracture stresses and toughnesses of the nanocomposite LBL layers, to assist in the implementation of a numerical crack band model that describes the nanocomposite film. The computational model predicts the failure of the ballistic nanocomposite samples, and the predicted V50 velocity is found to be in good agreement with

  18. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Science.gov (United States)

    Hui, Alex; Sheardown, Heather; Jones, Lyndon

    2012-01-01

    Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted) tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted) tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials. PMID:28817033

  19. Biocompatibility and bond degradation of poly-acrylic acid coated copper iodide-adhesives.

    Science.gov (United States)

    ALGhanem, Adi; Fernandes, Gabriela; Visser, Michelle; Dziak, Rosemary; Renné, Walter G; Sabatini, Camila

    2017-09-01

    To investigate the effect of poly-acrylic acid (PAA) copper iodide (CuI) adhesives on bond degradation, tensile strength, and biocompatibility. PAA-CuI particles were incorporated into Optibond XTR, Optibond Solo and XP Bond in 0.1 and 0.5mg/ml. Clearfil SE Protect, an MDPB-containing adhesive, was used as control. The adhesives were applied to human dentin, polymerized and restored with composite in 2mm-increments. Resin-dentin beams (0.9±0.1mm2) were evaluated for micro-tensile bond strength after 24h, 6 months and 1year. Hourglass specimens (10×2×1mm) were evaluated for ultimate tensile strength (UTS). Cell metabolic function of human gingival fibroblast cells exposed to adhesive discs (8×1mm) was assessed with MTT assay. Copper release from adhesive discs (5×1mm) was evaluated with UV-vis spectrophotometer after immersion in 0.9% NaCl for 1, 3, 5, 7, 10, 14, 21 and 30 days. SEM, EDX and XRF were conducted for microstructure characterization. XTR and Solo did not show degradation when modified with PAA-CuI regardless of the concentration. The UTS for adhesives containing PAA-CuI remained unaltered relative to the controls. The percent viable cells were reduced for Solo 0.5mg/ml and XP 0.1 or 0.5mg/ml PAA-CuI. XP demonstrated the highest ion release. For all groups, the highest release was observed at days 1 and 14. PAA-CuI particles prevented the bond degradation of XTR and Solo after 1year without an effect on the UTS for any adhesive. Cell viability was affected for some adhesives. A similar pattern of copper release was demonstrated for all adhesives. Copyright © 2017. Published by Elsevier Ltd.

  20. Electronically Stabilized Copoly(Styrene-Acrylic Acid Submicrocapsules Prepared by Miniemulsion Copolymerization

    Directory of Open Access Journals (Sweden)

    Minkwan Kim

    2017-07-01

    Full Text Available This work reports the preparation and characterization of poly(styrene-acrylic acid (St/AA submicrocapsules by using the miniemulsion copolymerization method. AA was introduced to miniemulsion polymerization of St to increase the zeta potential and the resulting electrostatic stability of St/AA submicrocapsules. Phytoncide oil was adopted as the core model material. Miniemulsion copolymerization of St and AA was conducted at a fixed monomer concentration (0.172 mol with a varying monomer feed ratio [AA]/[St] (0.2, 0.25, 0.33, 0.5, and 1.0. Concentrations of initiator (azobisisobutyronitrile; 1.0 × 10−3, 2.0 × 10−3, 3.0 × 10−3, and 4.0 × 10−3 mol/mol of monomer and surfactant (sodium dodecyl sulfate; 0.6 × 10−3, 1.0 × 10−3, and 1.4 × 10−3 mol were also controlled to optimize the miniemulsion copolymerization of St and AA. Dynamic light scattering and microscopic analyses confirmed the optimum condition of miniemulsion copolymerization of St and AA. Long-term colloidal stability of aqueous St/AA submicrocapsule suspension was evaluated by using TurbiscanTM Lab. In this work, the optimum condition for miniemulsion copolymerization of St and AA was determined ([AA]/[St] = 0.33; [SDS] = 1.0 × 10−3 mol; [AIBN] = 2.0 × 10−3 mol/mol of monomer. St/AA submicrocapsules prepared at the optimum condition (392.6 nm and −55.2 mV of mean particle size and zeta potential, respectively showed almost no variations in backscattering intensity (stable colloids without aggregation.

  1. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Directory of Open Access Journals (Sweden)

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

  2. The Effect of Double Crosslinker on Precipitation Polymerization of Poly(acrylic acid

    Directory of Open Access Journals (Sweden)

    Hajar Es-haghi

    2014-06-01

    Full Text Available Cross-linked poly(acrylic acids were prepared by dual cross-linkers via precipitation polymerization method in a binary organic solvent. Polyethylene glycol diacrylate (PEGDA-400 as a long-chain cross-linker and di(trimethylol propane tetraacrylate (DTMPTA as multifunctional cross-linker were used. PEGDA-400 was utilized to increase thickening properties and DTMPTA was used to improve the gel strength. The dual cross-linkers effect on the sample features (i.e., equilibrium swelling, thickening properties and rheological properties was investigated. Maximum amount of swelling was obtained by a high percentage of long-chain cross-linker. The apparent viscosity of the microgels was measured to determine their thickening properties for aqueous media. Maximum viscosity occurred at DT25-PE75 which was dependent on the type of cross-linkers in the polymer structure. The Flory-Rehner equation (from swelling ratio data and rubber elasticity theory (from rheometry data were used to discuss the network structure of the polymer. Increasing density of the network was shown by a sample containing high percentage of a four-functional cross-linker. The rheological properties of the cross-linked polymers were measured to determine storage modulus (strength network. The rheological behaviors demonstrated that the synthesized polymer containing a high amount of four-functional cross-linker had higher storage modulus (G′ than other samples. In addition the consistency coefficient (m and flow behavior index (n parameters of Ostwald equation were investigated as well. As a result, n values in each sample were found to be smaller than 1 and these results were fitted clearly with the pseudoplastic model. Apparent and rotational viscosities were used to determine the optimal cross-linker type (synthesized sample contained a high percentage of long-chain cross-linker.

  3. Oral peptide delivery: in-vitro evaluation of thiolated alginate/poly(acrylic acid) microparticles.

    Science.gov (United States)

    Greimel, Alexander; Werle, Martin; Bernkop-Schnürch, Andreas

    2007-09-01

    The purpose of this study was to develop an oral thiomer-based microparticulate delivery system for insulin by ionic gelation. The microparticulate matrix consisted of either poly(acrylic acid)-cysteine (PAA-Cys) and alginate-cysteine (Alg-Cys) or the corresponding unmodified polymers (PAA, Alg). Two different viscosities of alginates were provided for the study, low and medium. Three different types of microparticles were prepared via ionic gelation with calcium (Alg, AlgPAA and AlgPAA-Cys) and their different properties evaluated in-vitro (particle size and shape, drug loading and release profile, swelling and stability). The mean particle size of all formulations ranged from 400 to 600 microm, revealing the lowest for thiolated microparticles. SEM micrographs showed different morphological profiles for the three different types of microparticles. Encapsulation efficiency of insulin increased within the following rank order: Alg (15%) Alginate and AlgPAA microparticles displayed a burst release after 30 min, whereas the thiolated particles achieved a controlled release of insulin over 3 h. The swelling ratio was pH dependent: in simulated intestinal fluid microparticles exhibited a much higher water uptake compared with simulated gastric fluid. Due to the formation of intraparticulate disulfide bonds during the preparation process, thiolated particles revealed a higher stability. It was also observed that the viscosity of the two alginates used had no influence on the properties of the particles. According to these results AlgPAA-Cys microparticles obtained by ionic gelation and stabilized via disulfide bonds might be an alternative tool for the oral administration of therapeutic peptides.

  4. Acrylates in contact dermatitis.

    Science.gov (United States)

    Sasseville, Denis

    2012-01-01

    Acrylates are plastic materials that are formed by the polymerization of monomers derived from acrylic or methacrylic acid. They have found numerous applications in paints, varnishes and adhesives, in the printing industry, in the medical and dental professions, and in artificial nails. Beginning in the 1950s, many reports of occupational and nonoccupational allergic contact dermatitis to (meth)acrylate monomers have been published. These molecules are strong irritants, and patch testing can induce active sensitization. When patch tested, acrylate-allergic patients often display multiple positive tests. These reactions may represent cross-reactions, or concomitant reactions due to the presence, in the products responsible for sensitization, of impurities not disclosed in material safety data sheets. (Meth)acrylates are volatile and unstable chemicals, as demonstrated by their rapid disappearance from commercially available patch test allergens when exposed to air for more than a few hours.

  5. Treatment of psoriasis with non-registered fumaric acid esters in The Netherlands: a nationwide survey among Dutch dermatologists.

    Science.gov (United States)

    Fallah Arani, S; Balak, D M W; Neumann, H A M; Kuipers, M V; Thio, H B

    2014-07-01

    Psoriasis vulgaris is a T-cell mediated disease that affects 2-3% of the worldwide white-skinned population. Fumaric acid esters are mentioned as an effective therapy for moderate-to-severe psoriasis vulgaris in adult patients in the new guidelines for psoriasis treatment. To obtain an insight into the use of fumaric acid esters by Dutch dermatologists in the Netherlands. This was a cross-sectional postal survey. An anonymous survey was posted to all Dutch dermatologists. In this survey, data were collected on the extent of fumaric acid esters use, the reasons for use, the reasons for non- or limited use of fumaric acid esters, the perception of fumaric acid esters as a mono-therapy with regards to the effectiveness, the safety, the adverse events and the overall satisfaction of fumaric acid esters as a mono-therapy. Sixty-three per cent of the 300 responders indicated to prescribe fumaric acid esters for the treatment of psoriasis. About 37% of the dermatologists indicated (almost) never to prescribe it. Biologicals were considered as the most effective therapy. Fumaric acid esters were regarded as the safest therapy. They were generally well-tolerated by the patients similar to that for methotrexate according to the respondents. A large proportion of the dermatologists in our survey indicated to prescribe fumaric acid esters. It is considered to be effective, safe and without adverse events profile that is favourable in the practice, also as compared with other systemic therapies such as methotrexate and biologicals. © 2013 European Academy of Dermatology and Venereology.

  6. The Synthesis and Evaluation of Arctigenin Amino Acid Ester Derivatives.

    Science.gov (United States)

    Cai, En-Bo; Yang, Li-Min; Jia, Cai-Xia; Zhang, Wei-Yuan; Zhao, Yan; Li, Wei; Song, Xing-Zhuo; Zheng, Man-Ling

    2016-10-01

    The use of arctigenin (ARG), a traditional medicine with many pharmacological activities, has been restricted due to its poor solubility in water. Five amino acid derivatives of ARG have been synthesized using glycine, o-alanine, valine, leucine, and isoleucine, which have t-butyloxy carbonyl (BOC) as a protective group. In this study, we examined the effects of removing these protective groups. The results showed that the amino acid derivatives have better solubility and nitrite-clearing ability than ARG. Among the compounds tested, the amino acid derivatives without protective group were the best. Based on these results, ARG and its two amino acid derivatives without protective group (ARG8, ARG10) were selected to evaluate their anti-tumor activity in vivo at a dosage of 40 mg/kg. The results indicated that ARG8 and ARG10 both exhibit more anti-tumor activity than ARG in H22 tumor-bearing mice. The tumor inhibition rates of ARG8 and ARG10 were 69.27 and 43.58%, which was much higher than ARG. Furthermore, the mice treated with these compounds exhibited less damage to the liver, kidney and immune organs compared with the positive group. Furthermore, ARG8 and ARG10 improved the serum cytokine levels significantly compared to ARG. In brief, this study provides a method to improve the water solubility of drugs, and we also provide a reference basis for new drug development.

  7. SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT ...

    African Journals Online (AJOL)

    eobe

    where R is a mixture of various fatty acid chains. Generally, transesterification is a reversible reaction, although in the production of biodiesel, the backward reaction does not occur or is negligible because the glycerol formed is not miscible with the product, leading to a two-phase system. Nevertheless, an excess of alcohol ...

  8. Chair interconversion and reactivity of mannuronic acid esters

    NARCIS (Netherlands)

    Ronnols, Jerk; Walvoort, Marthe T. C.; van der Marel, Gijsbert A.; Codee, Jeroen D. C.; Widmalm, Goran

    2013-01-01

    Mannopyranosyluronic acids display a very unusual conformation behavior in that they often prefer to adopt a C-1(4) chair conformation. They are endowed with a strikingly high reactivity when used in a glycosylation reaction as a glycosyl donor. To investigate the unusual conformational behavior a

  9. 40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetic acid, 2-chloro-, 1-(3,3... Specific Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester. (a... acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester (PMN P-05-568; CAS No. 477218-59-0) is...

  10. Linear and cyclic ester Oligomers of succinic acid and 1,4-butanediol: Biocatalytic synthesis and characterization

    NARCIS (Netherlands)

    Habeych Narvaez, D.I.; Eggink, G.; Boeriu, C.G.

    2011-01-01

    The lipase-catalyzed synthesis of cyclic ester oligomers from non-activated succinic acid (A) and 1,4-butanediol (B) in the presence of immobilized Candida antarctica lipase B was investigated. Batch and pulse fed-batch systems were implemented to increase the formation of cyclic ester products. The

  11. Occurrence of fatty acid short-chain-alkyl esters in fruits of Celastraceae plants.

    Science.gov (United States)

    Sidorov, Roman A; Zhukov, Anatoly V; Pchelkin, Vasily P; Vereshchagin, Andrei G; Tsydendambaev, Vladimir D

    2013-06-01

    Small amounts of a mixture of fatty acid short-chain-alkyl esters (FASCAEs) were obtained from the fruits of twelve plant species of Celastraceae family, and in five of them the FASCAEs were present not only in the arils but also in the seeds. These mixtures contained 32 individual FASCAE species, which formed four separate fractions, viz. FA methyl, ethyl, isopropyl, and butyl esters (FAMEs, FAEEs, FAIPEs, and FABEs, resp.). The FASCAE acyl components included the residues of 16 individual C₁₄-C₂₄ saturated, mono-, di-, and trienoic FAs. Linoleic, oleic, and palmitic acids, and, in some cases, also α-linolenic acid predominated in FAMEs and FAEEs, while myristic acid was predominant in FAIPEs. It can be suggested that, in the fruit arils of some plant species, FAMEs and FAEEs were formed at the expense of a same FA pool characteristic of a given species and were strongly different from FAIPEs and FABEs esters regarding the mechanism of their biosynthesis. However, as a whole, the qualitative and quantitative composition of various FASCAE fractions, as well as their FA composition, varied considerably depending on various factors. Therefore, separate FASCAE fractions seem to be synthesized from different FA pools other than those used for triacylglycerol formation. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  12. Fumaric Acid and its Esters: An Emerging Treatment for Multiple Sclerosis

    Science.gov (United States)

    Moharregh-Khiabani, D; Linker, R.A; Gold, R; Stangel, M

    2009-01-01

    Fumaric acid is an intermediate product of the citric acid cycle that is a source of intracellular energy in the form of adenosine triphosphate (ATP). It is generated by oxidation of adenylsuccinate by the enzyme succinate dehydrogenase and is then converted to maleate by the enzyme fumarase. At present, fumaric acid esters (FAE) are licensed for the treatment of psoriasis. Several lines of evidence have demonstrated immunomodulatory effects for FAE. Clinical studies in psoriasis showed a reduction of peripheral CD4+- and CD8+-T-lymphocytes due to the ability of FAE to induce apoptosis. In vitro studies with the ester dimethyl fumarate (DMF) described an inhibitory effect on nuclear factor kappa B (NF-κB)-dependent transcription of tumor necrosis factor-alpha (TNF-α) induced genes in human endothelial cells. Animal studies using a model of central nervous system demyelination, MOG-induced experimental autoimmune encephalomyelitis (EAE), revealed a reduction of microglia and macrophages in inflamed lesions. A phase II clinical study in relapsing-remitting multiple sclerosis (RRMS) patients with a modified fumaric acid ester, BG-12, showed as "proof of principle" a significant reduction in the number of gadolinium enhancing lesions after 24 weeks of treatment as compared to placebo. Further phase III studies have now started to explore the long-term efficacy of FAE. PMID:19721818

  13. Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc

    Directory of Open Access Journals (Sweden)

    Mohamed Touaibia

    2012-12-01

    Full Text Available Caffeic acid phenethyl ester (CAPE is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system.

  14. Synthesis and antiradical/antioxidant activities of caffeic acid phenethyl ester and its related propionic, acetic, and benzoic acid analogues.

    Science.gov (United States)

    LeBlanc, Luc M; Paré, Aurélie F; Jean-François, Jacques; Hébert, Martin J G; Surette, Marc E; Touaibia, Mohamed

    2012-12-10

    Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system.

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

    Directory of Open Access Journals (Sweden)

    Sandhya V G Nair

    Full Text Available Phloridzin (phlorizin or phloretin 2'-O-glucoside is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases IIα activity that might induce G0/G1 phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA ester of phloridzin was selected for gene expression analysis using RT2PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2, growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK, cell cycle machinery (CDKs, TERT, TOP2A, TOP2B as well as epigenetics regulators (HDACs. These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects

  16. Production of alpha-hydroxy carboxylic acids and esters from higher sugars using tandem catalyst systems

    Energy Technology Data Exchange (ETDEWEB)

    Orazov, Marat; Davis, Mark E.

    2017-11-07

    The present disclosure is directed to methods and composition used in the preparation of alpha-hydroxy carboxylic acids and esters from higher sugars using a tandem catalyst system comprising retro-aldol catalysts and Lewis acid catalysts. In some embodiments, these alpha-hydroxy carboxylic acids may be prepared from pentoses and hexoses. The retro-aldol and Lewis catalysts may be characterized by their respective ability to catalyze a 1,2-carbon shift reaction and a 1,2-hydride shift reaction on an aldose or ketose substrate.

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

    Directory of Open Access Journals (Sweden)

    Eva Vavříková

    2016-06-01

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

  18. Tuning of thermally induced sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid).

    Science.gov (United States)

    Jin, Naixiong; Zhang, Hao; Jin, Shi; Dadmun, Mark D; Zhao, Bin

    2012-03-15

    We report in this article a method to tune the sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers that consist of two blocks exhibiting distinct lower critical solution temperatures (LCSTs) in water. A small amount of weak acid groups is statistically incorporated into the lower LCST block so that its LCST can be tuned by varying solution pH. Well-defined diblock copolymers, poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid) (PTEGMA-b-P(DEGEA-co-AA)), were prepared by reversible addition-fragmentation chain transfer polymerization and postpolymerization modification. PTEGMA and PDEGEA are thermosensitive water-soluble polymers with LCSTs of 58 and 9 °C, respectively, in water. A 25 wt % aqueous solution of PTEGMA-b-P(DEGEA-co-AA) with a molar ratio of DEGEA to AA units of 100:5.2 at pH = 3.24 underwent multiple phase transitions upon heating, from a clear, free-flowing liquid (<15 °C) to a clear, free-standing gel (15-46 °C) to a clear, free-flowing hot liquid (47-56 °C), and a cloudy mixture (≥57 °C). With the increase of pH, the sol-to-gel transition temperature (T(sol-gel)) shifted to higher values, while the gel-to-sol transition (T(gel-sol)) and the clouding temperature (T(clouding)) of the sample remained essentially the same. These transitions and the tunability of T(sol-gel) originated from the thermosensitive properties of two blocks of the diblock copolymer and the pH dependence of the LCST of P(DEGEA-co-AA), which were confirmed by dynamic light scattering and differential scanning calorimetry studies. Using the vial inversion test method, we mapped out the C-shaped sol-gel phase diagrams of the diblock copolymer in aqueous buffers in the moderate concentration range at three different pH values (3.24, 5.58, and 5.82, all measured at ~0 °C). While the upper temperature boundaries overlapped, the lower temperature boundary

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-15

    Coriander (Coriandrum sativum L.) seed oil methyl esters were prepared and evaluated as an alternative biodiesel fuel and contained an unusual fatty acid hitherto unreported as the principle component in biodiesel fuels: petroselinic (6Z-octadecenoic; 68.5 wt%) acid. Most of the remaining fatty acid profile consisted of common 18 carbon constituents such as linoleic (9Z,12Z-octadeca-dienoic; 13.0 wt%), oleic (9Z-octadecenoic; 7.6 wt%) and stearic (octadecanoic; 3.1 wt%) acids. A standard transesterification procedure with methanol and sodium methoxide catalyst was used to provide C. sativum oil methyl esters (CSME). Acid-catalyzed pretreatment was necessary beforehand to reduce the acid value of the oil from 2.66 to 0.47 mg g{sup -1}. The derived cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of CSME was 53.3, 4.21 mm{sup 2} s{sup -1} (40 C), and 14.6 h (110 C). The cold filter plugging and pour points were -15 C and -19 C, respectively. Other properties such as acid value, free and total glycerol content, iodine value, as well as sulfur and phosphorous contents were acceptable according to the biodiesel standards ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color, along with a comparison of CSME to soybean oil methyl esters (SME). CSME exhibited higher oxidative stability, superior low temperature properties, and lower iodine value than SME. In summary, CSME has excellent fuel properties as a result of its unique fatty acid composition. (author)

  20. Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator.

    Science.gov (United States)

    Ilmi, Miftahul; Abduh, Muhammad Y; Hommes, Arne; Winkelman, Jozef G M; Hidayat, Chusnul; Heeres, Hero J

    2018-01-17

    Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)- water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous centrifugal contactor separator (CCCS), the latter being used for integrated reaction and liquid-liquid separation. A fatty acid butyl ester yield up to 93% was obtained in the cascade when operated in a once-through mode. The cascade was run for 8 h without operational issues. Enzyme recycling was studied by reintroduction of the water phase from the CCCS outlet to the stirred tank reactor. Product yield decreased over time to an average of 50% of the initial value, likely due to accumulation of 1-butanol in water phase, loss of enzyme due to agglomeration, and the formation of a separate enzyme layer.

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

    Science.gov (United States)

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

    2014-12-26

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

  2. Possible molecular targets for therapeutic applications of caffeic acid phenethyl ester in inflammation and cancer

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2015-03-01

    Full Text Available Of the various derivatives of caffeic acid, caffeic acid phenethyl ester (CAPE is a hydrophobic, bioactive polyphenolic ester obtained from propolis extract. The objective in writing this review article was to summarize all published studies on therapeutics of CAPE in inflammation and cancer to extract direction for future research. The possible molecular targets for the action of CAPE, include various transcription factors such as nuclear factor-κB, tissue necrosis factor-α, interleukin-6, cyclooxygenase-2, Nrf2, inducible nitric oxide synthase, nuclear factor of activated T cells, hypoxia-inducible factor-1α, and signal transducers and activators of transcription. Based on the valuable data on its therapeutics in inflammation and cancer, clinical studies of CAPE should also be conducted to explore its toxicities, if any.

  3. Headspace solid-phase microextraction of higher fatty acid ethyl esters in white rum aroma.

    Science.gov (United States)

    Pino, J; Martí, M P; Mestres, M; Pérez, J; Busto, O; Guasch, J

    2002-04-19

    Fatty acid ethyl esters are the main components of rum aroma and play an important sensorial impact in these distilled alcoholic beverages. Herein, a method for analysing these volatile compounds is described. It involves a separation and concentration step using headspace solid-phase microextraction and determination by capillary gas chromatography using flame ionisation detection. The influence of different parameters related to the isolation and concentration step, such as ethanol concentration, ionic strength, sample volume, time and temperature of extraction, was studied. The developed method enabled recoveries >91% for the analyzed compounds with limits of detection between 0.007 and 0.027 mg/l, all of them lower than the range of concentrations found in rum samples. The method was successfully applied to the analysis of fatty acid ethyl esters in different commercial white rums.

  4. Chemical Constituents from Flueggea virosa and the Structural Revision of Dehydrochebulic Acid Trimethyl Ester

    Directory of Open Access Journals (Sweden)

    Chih-Hua Chao

    2016-09-01

    Full Text Available In an attempt to study the chemical constituents from the twigs and leaves of Flueggea virosa, a new terpenoid, 9(10→20-abeo-ent-podocarpane, 3β,10α-dihydroxy-12-methoxy-13- methyl-9(10→20-abeo-ent-podocarpa-6,8,11,13-tetraene (1, as well as five known compounds were characterized. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the structure of dehydrochebulic acid trimethyl ester was revised as (2S,3R-4E-dehydrochebulic acid trimethyl ester based on a single-crystal X-ray diffraction study. The in vitro anti-hepatitis C virus (anti-HCV activity and cytotoxicity against Huh7.5 cells for the isolated compounds were evaluated.

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

    Science.gov (United States)

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

    2017-03-01

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

  6. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester

    Science.gov (United States)

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

    1985-01-01

    Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

  7. Synthesis of hollow silver spheres using poly-(styrene-methyl acrylic acid) as templates in the presence of sodium polyacrylate

    Science.gov (United States)

    Wang, Aili; Yin, Hengbo; Ge, Chen; Ren, Min; Liu, Yumin; Jiang, Tingshun

    2010-02-01

    Hollow silver spheres were successfully prepared by reducing AgNO 3 with ascorbic acid and using negatively charged poly-(styrene-methyl acrylic acid) (PSA) spheres as templates in the presence of sodium polyacrylate as a stabilizer. Firstly, silver cations adsorbed on the surface of PSA spheres via electrostatic attraction between the carboxyl groups and silver cations were reduced in situ by ascorbic acid. The silver nanoparticles deposited on the surface of PSA spheres served as seeds for the further growth of silver shells. After that, extra amount of AgNO 3 and ascorbic acid solutions were added to form PSA/Ag composites with thick silver shells. In order to obtain compact silver shells, the as-prepared PSA/Ag composites were heated at 150 °C for 3 h. Then hollow silver spheres were prepared by dissolving PSA templates with tetrahydrofuran.

  8. Decomposition products of glycidyl esters of fatty acids by heating.

    Science.gov (United States)

    Kimura, Wataru; Endo, Yasushi

    2017-03-01

    In this study, decomposition products of glycidyl palmitate (GP) of fatty acids heated at high temperature such as deep frying were investigated. When GP and tripalmitin (TP) were heated at 180 and 200 °C, they were decreased with heating time. The weight of GP was less than that of TP, although both GP and TP were converted to polar compounds after heating. The decomposition rate of GP was higher than TP. Both GP and TP produced considerable amounts of hydrocarbons and aldehydes during heating. Aldehydes produced from GP and TP included saturated aldehydes with carbon chain length of 3-10, while hydrocarbons consisted of carbon chain length of 8-15. It was observed that major hydrocarbons produced from GP during heating were pentadecane. Moreover, the level of carbon dioxide (CO2) released from GP was higher than that of TP. It was suggested that fatty acids in GE might be susceptible to decarboxylation. From these results, GP might be quickly decomposed to hydrocarbons, aldehydes and CO2 besides polar compounds by heating, in comparison with TP.

  9. Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.

    Science.gov (United States)

    Ruiz, Sara Melisa Arciniegas; Olvera, Lilia Gutiérrez; Chacón, Sara del Carmen Caballero; Estrada, Dinorah Vargas

    2015-04-01

    To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices. 30 healthy adult dogs. In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment. Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment. Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 μg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.

  10. Influence of TNF-alpha inhibitors and fumaric acid esters on male fertility in psoriasis patients.

    Science.gov (United States)

    Heppt, F; Colsman, A; Maronna, A; Uslu, U; Heppt, M V; Kiesewetter, F; Sticherling, M

    2017-11-01

    Is there any influence of a therapy with TNF-alpha inhibitors or fumaric acid esters and of disease activity status on male fertility and sperm quality in patients with psoriasis? In this monocentric, open-label, prospective study, semen samples were collected from patients receiving either TNF-alpha inhibitors or fumaric acid esters for moderate-to-severe plaque psoriasis. Semen was analysed at baseline before onset of the systemic therapy and monitored every 3 months under therapy. Sperm parameters were assessed according to the current WHO definitions. In total, 101 semen specimens from 27 patients were obtained. Mean Psoriasis Area and Severity Index (PASI) score at baseline was 11.05. Only 14.8% of patients showed a normozoospermia without any other abnormal seminal values. 85.2% of patients had at least one sperm/seminal abnormality, including two patients showing an azoospermia. Interestingly, 48.1% showed sperm parameters indicative of genital tract inflammation. Therapy with TNF-alpha inhibitors or fumaric acid esters did not have any negative effects on relevant sperm parameters such as mean total sperm number, sperm concentration, total and progressive motility. No major gonadal dysfunction was observed in any patient. At baseline, many patients with psoriasis showed abnormal semen/sperm parameters and remarkably elevated leukocytes and values of seminal polymorphonuclear elastase, indicating a genital tract inflammation. Thus, genital tract inflammation may represent an important comorbidity of psoriasis, little attention paid to so far. Regarding treatment with TNF-alpha inhibitors or fumaric acid esters, no major negative (side-) effects on sperm quality were observed. © 2017 European Academy of Dermatology and Venereology.

  11. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: A case series

    OpenAIRE

    Balak, Deepak; Bavinck, Jan Nico Bouwes; De Vries, A.P.J. (Aiko P. J.); Hartman, J.; Martino Neumann, H.A.; Zietse, Bob; Thio, Bing

    2016-01-01

    textabstractBackground: Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fanconi syndrome. Methods: Descriptive case series with two cases of Fanconi syndrome associated with FAE treatment diagnosed at two Dutch university nephrology departments, three cases reported at th...

  12. Oral fumaric acid esters for psoriasis: abridged Cochrane systematic review including GRADE assessments

    OpenAIRE

    Atwan, A.; Ingram, John R.; Abbott, Rachel; Kelson, Mark James; Pickles, Timothy E.; Bauer, A.; Piguet, Vincent

    2016-01-01

    Summary Fumaric acid esters (FAEs) are licensed for the treatment of moderate?to?severe psoriasis in Germany but are also used off?label in many other countries. We conducted this systematic review to synthesize the highest?quality evidence for the benefits and risks of FAEs for psoriasis. Our primary outcomes were change in Psoriasis Area and Severity Index score and dropout rates due to adverse effects. Randomized controlled trials (RCTs) of FAEs or dimethylfumarate were included, with no r...

  13. Improvement of foaming properties of cuttlefish skin gelatin by modification with N-hydroxysuccinimide esters of fatty acid

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Wierenga, P.A.; Gruppen, H.

    2011-01-01

    Conformation and foaming properties of cuttlefish skin gelatin modified by N-hydroxysuccinimide esters of different saturated fatty acids including capric acid (C10:0), lauric acid (C12:0) and myristic acid (C14:0) at different molar ratios (0.25, 0.50, 1.00 and 2.00) were investigated. Covalent

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-15

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

  15. Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution

    OpenAIRE

    ALEKSANDAR KOSTIC; BORIVOJ ADNADJEVIC; ALEKSANDAR POPOVIC; JELENA JOVANOVIC

    2007-01-01

    The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ºC were determined. The possibility of applying both the Fick’s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of ...

  16. Biocompatibility of poly(ethylene glycol) and poly(acrylic acid) interpenetrating network hydrogel by intrastromal implantation in rabbit cornea

    OpenAIRE

    Zheng, Luo Luo; Vanchinathan, Vijay; Dalal, Roopa; Noolandi, Jaan; Waters, Dale J.; Hartmann, Laura; Cochran, Jennifer R.; Frank, Curtis W.; Yu, Charles Q.; Ta, Christopher N.

    2015-01-01

    We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 m...

  17. Preparation of Superabsorbent Resin from Carboxymethyl Cellulose Grafted with Acrylic Acid by Low-temperature Plasma Treatment

    OpenAIRE

    Li Jie Huang; Ying Yang; Yuan Yuan Cai; Ming Liu; Ting Xu; Guang Zai Nong; Shuang Fei Wang

    2014-01-01

    A superabsorbent resin (SAR) synthesized from carboxymethyl cellulose (CMC) by grafting acrylic acid (AA) was studied using single-factor analysis. The optimum preparation conditions were as follows: plasma discharge power of 250 W, processing time of 90 s, pressure of 300 Pa, m(CMC):m(AA) ratio of 1:9, m(K2S2O8):m(CMC) ratio of 1:4, and neutralization degree of 40%. Under these conditions, the resin has a salt water absorbency of 38.5 g/g and a stable chlorine dioxide solution absorbency of ...

  18. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with boric...

  19. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

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

  20. Molecularly imprinted films of acrylonitrile/methyl methacrylate/acrylic acid terpolymers: influence of methyl methacrylate in the binding performance of L-ephedrine imprinted films.

    Science.gov (United States)

    Brisbane, Carrie; McCluskey, Adam; Bowyer, Michael; Holdsworth, Clovia I

    2013-05-07

    Molecularly imprinted polymeric films (MIPFs) highly selective to 1R,2S(-)ephedrine (L-ephedrine, EPD) were produced by phase inversion post-polymerization imprinting on poly(acrylonitrile-co-methyl methacrylate-co-acrylic acid) (PAMA) terpolymers. The inclusion of methyl methacrylate (MMA) to the polymer formulation resulted in enhanced EPD selectivity which appears to be dictated by polymer composition to achieve the necessary balance between polymer rigidity and porosity. Substitution of MMA with methyl acrylate, ethyl acrylate and n-butyl acrylate resulted in a loss of EPD selectivity and EPD entrapment within the polymer matrix not observed in PAMA MIPFs. MMA, by virtue of its methyl group, is able to provide the scaffolding and rigidity necessary for stability and preservation of imprinted cavities within the PAMA MIPF leading to high EPD selectivity.

  1. One-Pot Synthesis of Esters of Cyclopropane Carboxylic Acids via Tandem Vicarious Nucleophilic Substitution-Michael Addition Process.

    Science.gov (United States)

    Mąkosza, Mieczysław; Bester, Karol; Cmoch, Piotr

    2015-06-05

    α-Chlorocarbanions generated via base-induced vicarious nucleophilic substitution reaction of alkyl dichloroacetates with nitroarenes react with Michael acceptors to give esters of cyclopropane carboxylic acids substituted with p-nitroaromatic rings.

  2. Chemically Cross-Linked Poly(acrylic-co-vinylsulfonic Acid Hydrogel for the Delivery of Isosorbide Mononitrate

    Directory of Open Access Journals (Sweden)

    Talib Hussain

    2013-01-01

    Full Text Available We report synthesis, characterization, and drug release attributes of a series of novel pH-sensitive poly(acrylic-co-vinylsulfonic acid hydrogels. These hydrogels were prepared by employing free radical polymerization using ethylene glycol dimethacrylate (EGDMA and benzyl peroxide (BPO as cross-linker and initiator, respectively. Effect of acrylic acid (AA, polyvinylsulfonic acid (PVSA, and EGDMA on prepared hydrogels was investigated. All formulations showed higher swelling at high pHs and vice versa. Formulations containing higher content of AA and EGDMA show reduced swelling, but one with higher content of PVSA showed increased swelling. Hydrogel network was characterized by determining structural parameters and loaded with isosorbide mononitrate. FTIR confirmed absence of drug polymer interaction while DSC and TGA demonstrated molecular dispersion of drug in a thermally stable polymeric network. All the hydrogel formulations exhibited a pH dependent release of isosorbide mononitrate which was found to be directly proportional to pH of the medium and PVSA content and inversely proportional to the AA contents. Drug release data were fitted to various kinetics models. Results indicated that release of isosorbide mononitrate from poly(AA-co-VSA hydrogels was non-Fickian and that the mechanism was diffusion-controlled.

  3. Why are esters and amides weaker carbon acids than ketones and Acid fluorides? Contributions by resonance and inductive effects.

    Science.gov (United States)

    Fersner, Alexandra; Karty, Joel M; Mo, Yirong

    2009-10-02

    Two computational methodologies-a vinylogue extrapolation methodology and a block localized wave function (BLW) methodology-were employed to determine the contributions by resonance and inductive effects toward the gas-phase deprotonation enthalpies at the alpha carbons of acetone, acetamide, acetic acid, and acetyl fluoride, which were taken to be model compounds for ketones, amides, esters, and acid fluorides, respectively. Results from the vinylogue methodology suggest that resonance serves to enhance the gas-phase deprotonation enthalpy of a ketone by 34.3 kcal/mol, an amide by 26.2 kcal/mol, an ester by 30.5 kcal/mol, and an acid fluoride by 30.8 kcal/mol. Comparably, the BLW methodology suggests those numbers to be 42.3, 31.2, 36.1, and 39.7 kcal/mol, respectively. Results from the vinylogue methodology suggest that inductive effects serve to enhance the gas-phase deprotonation enthalpy of a ketone by 11.8 kcal/mol, an amide by 12.7 kcal/mol, an ester by 15.5 kcal/mol, and an acid fluoride by 26.0 kcal/mol, and in the same order, those numbers suggested by the BLW methodology are 3.0, 6.2, 8.5, and 16.3 kcal/mol.

  4. Comparative study of the self-aggregation of rhodamine 6G in the presence of poly(sodium 4-styrenesulfonate), poly(N-phenylmaleimide-co-acrylic acid), poly(styrene-alt-maleic acid), and poly(sodium acrylate).

    Science.gov (United States)

    Moreno-Villoslada, Ignacio; Fuenzalida, Juan Pablo; Tripailaf, Gustavo; Araya-Hermosilla, Rodrigo; Pizarro, Guadalupe del C; Marambio, Oscar Guillermo; Nishide, Hiroyuki

    2010-09-23

    The interaction between rhodamine 6G and different polyelectrolytes is analyzed. Structural aspects differentiate these polyelectrolytes, such as the presence of aromatic groups and the number and localization of their respective charges, which may be directly attached to the aromatic groups or to the polymeric main chain. In the case of poly(sodium acrylate), which does not bear aromatic groups, the polyelectrolyte induces cooperative self-stacking between the dyes which is highly sensitive to the ionic strength, due to the predominance of long-range electrostatic interactions between the polymer and the dye. In the case of poly(sodium 4-styrenesulfonate), whose charge is directly attached to the aromatic groups, a high dispersant ability of the dyes is found and the interaction is less dependent on the ionic strength, due to the predominance of short-range aromatic-aromatic interactions between the dye and the polymer. Among the two polyelectrolytes studied for which the polymeric charge is directly attached to the main chain, and separated from the aromatic group, poly(styrene-alt-maleic acid) shows a lower dependence of the interaction on the ionic strength than poly(N-phenylmaleimide-co-acrylic acid) at a comonomer composition of 1:2, due to a higher linear aromatic density and a lower linear charge density, indicating the importance of hydrophobic forces. Both copolymers exhibit a high ability to induce cooperative self-aggregation of the dye.

  5. Isolation and Characterization of Esters of Indole-3-Acetic Acid from the Liquid Endosperm of the Horse Chestnut (Aesculus species) 1

    Science.gov (United States)

    Domagalski, Wojciech; Schulze, Aga; Bandurski, Robert S.

    1987-01-01

    Esters of indole-3-acetic acid were extracted and purified from the liquid endosperm of immature fruits of various species of the horse chestnut (Aesculus parviflora, A. baumanni, A.pavia rubra, and A. pavia humulis). The liquid endosperm contained, at least 12 chromatographically distinct esters. One of these compounds was purified and characterized as an ester of indole-3-acetic acid and myo-inositol. A second compound was found to be an ester of indole-3-acetic acid and the disaccharide rutinose (glucosyl-rhamnose). A third compound was partially characterized as an ester of indole-3-acetic acid and a desoxyaminohexose. PMID:11539676

  6. Integrated process of distillation with side reactors for synthesis of organic acid esters

    Science.gov (United States)

    Panchal, Chandrakant B; Prindle, John C; Kolah, Aspri; Miller, Dennis J; Lira, Carl T

    2015-11-04

    An integrated process and system for synthesis of organic-acid esters is provided. The method of synthesizing combines reaction and distillation where an organic acid and alcohol composition are passed through a distillation chamber having a plurality of zones. Side reactors are used for drawing off portions of the composition and then recycling them to the distillation column for further purification. Water is removed from a pre-reactor prior to insertion into the distillation column. An integrated heat integration system is contained within the distillation column for further purification and optimizing efficiency in the obtaining of the final product.

  7. Phenolic Acid-based Poly(anhydride-esters) as Antioxidant Biomaterials.

    Science.gov (United States)

    Prudencio, Almudena; Faig, Jonathan J; Song, MinJung; Uhrich, Kathryn E

    2016-02-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic acids. Further, the released phenolic acids were found to maintain antioxidant potency relative to free phenolic acid controls as determined by a 2,2-diphenyl-1-picrylhydrazyl assay. Polymer cytotoxicity was assessed with L929 fibroblasts in polymer-containing media; appropriate cell morphology and high fibroblast proliferation were obtained for the polymers at the lower concentrations. These polymers deliver non-cytotoxic levels of naturally occurring antioxidants, which could be efficacious in topical delivery of antioxidant therapies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Treatment of severe psoriasis with fumaric acid esters: scientific background and guidelines for therapeutic use. The German Fumaric Acid Ester Consensus Conference.

    Science.gov (United States)

    Mrowietz, U; Christophers, E; Altmeyer, P

    1999-09-01

    Fumaric acid ester (FAE) therapy has proved to be safe and effective in patients with severe psoriasis vulgaris. This treatment was introduced nearly 30 years ago, but is only now gaining renewed interest among dermatologists. FAE therapy is licensed in Germany and registration is pending in many European countries. Multicentre trials have confirmed the beneficial effect of FAE in psoriasis and have defined the spectrum of its adverse effects. Although the mode of action of FAEs in the treatment of psoriasis is not fully understood, recent experimental data point towards a skewing of the Th1-dominated T-cell response in psoriasis to a Th2-like pattern, and inhibition of proliferation of keratinocytes. This article reviews the experimental and clinical information on FAEs in psoriasis and provides guidelines for the clinical use of FAEs derived from a consensus meeting of leading experts.

  9. Direct synthesis of esters and amides from unprotected hydroxyaromatic and -aliphatic carboxylic acids.

    Science.gov (United States)

    Katritzky, Alan R; Singh, Sanjay K; Cai, Chunming; Bobrov, Sergey

    2006-04-28

    A facile method for the activation of hydroxy-substituted carboxylic acids using benzotriazole chemistry without prior protection of the hydroxy substituents is presented. The N-acylbenzotriazole intermediates 2a-g, 6a-d, and 9a-c have been used for high-yielding synthesis of both aliphatic (3a-l) and aromatic (7a-h, 10a-f) hydroxy carboxamides. High yields of aromatic hydroxy esters 12a-h and 13a-i were obtained using either neat alcohols in neutral microwave conditions or nucleophilic alkoxides and the intermediate N-(arylacyl)benzotriazoles. Moderate yields were obtained in the case of aliphatic hydroxy esters 11a,b and thiolesters 11e-g from the intermediates 2a-c.

  10. Synthesis and immunomodulatory activites of new 5-hydrazino-3-methyl-4-isothiazolecarboxylic acid ethyl esters.

    Science.gov (United States)

    Lipnicka, Urszula; Maczyński, Marcin; Artym, Jolanta; Zimecki, Michał

    2009-01-01

    Several new derivatives of 5-hydrazino-3-methyl-4-isothiazolecarboxylic ethyl esters were synthesized. Using 4-aminoacetophenone, the hydrazine group was transformed in position 5 in the hydrazone which reacted with the isocyanates, aldehydes and sugars. Thirteen newly synthesized compounds were tested for their ability to affects the immunological response in vitro in several rodent models. The immunoregulatory properties of the compounds were differential and dose-dependent. The strongest activity was exhibited by 5-{N'-[1-4{-4-[3-(-methoxyphenyl)-ureidol]-phenylethylidene]-hydrazino}-3-methyl-4-isothiazolecarboxylic acid ethyl ester (compound 3a). The compound strongly inhibited the secondary, humoral immune response to sheep erythrocytes and the proliferative response of mouse splenocytes to concanavalin A and pokeweed mitogen. The immunotropic activities of the new isothiazole derivatives and potential application of the compounds in therapy are discussed.

  11. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    Science.gov (United States)

    Wei, Liangming; Chen, Changxin; Hou, Zhongyu; Wei, Hao

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dimensional binders, the NaPAA-g-CMC copolymer binder is expected to present multi-point interaction with Si surface, resulting in enhanced binding ability with Si particles as well as with the copper (Cu) current collectors, and building a stable solid electrolyte interface (SEI) layer on the Si surface. The NaPAA-g-CMC based Si anode shows much better cycle stability and higher coulombic efficiency than those made with the well-known linear polymeric binders such as CMC and NaPPA. PMID:26786315

  12. Developing the potential ophthalmic applications of pilocarpine entrapped into polyvinylpyrrolidone-poly(acrylic acid) nanogel dispersions prepared by γ radiation.

    Science.gov (United States)

    Abd El-Rehim, Hassan A; Swilem, Ahmed E; Klingner, Anke; Hegazy, El-Sayed A; Hamed, Ashraf A

    2013-03-11

    The aim of this study was to improve the stability and bioavailability of pilocarpine in order to maintain an adequate concentration of the pilocarpine at the site of action for prolonged period of time. Thus, pH-sensitive polyvinylpyrrolidone-poly(acrylic acid) (PVP/PAAc) nanogels prepared by γ radiation-induced polymerization of acrylic acid (AAc) in an aqueous solution of polyvinylpyrrolidone (PVP) as a template polymer were used to encapsulate pilocarpine. Factors affecting size and encapsulation efficiency were optimized to obtain nanogel suitable for entrapping drug efficiently. The PVP/PAAc nanogel particles were characterized by dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), and their size can be controlled by the feed composition and concentration as well as the irradiation dose. Pilocarpine was loaded into the nanogel particles through electrostatic interactions where the AAc-rich nanogels exhibited the highest loading efficiency. The transmittance, mucoadhesion, and rheological characteristics of the nanogel particles were studied to evaluate their ocular applicability. The in vitro release study conducted in simulated tear fluid showed a relatively long sustained release of pilocarpine from the prepared PVP/PAAc nanogel particles if compared with pilocarpine in solution.

  13. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  14. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Song, Cunfeng [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Chang, Ying; Cheng, Ling; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Zhang, Long; Zhong, Lina [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China)

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. - Highlights: • A new type of antibacterial agent (PSA/Ag-NPs nanocomposites) was synthesized. • The antibacterial activity against S. aureus and E. coli was studied. • Inhibition zone, MIC, MBC, and bactericidal kinetics were evaluated. • PSA/Ag-NPs nanocomposites showed excellent antibacterial activity.

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

    OpenAIRE

    Samosir, Yustina

    2011-01-01

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

  16. GESTATIONAL-AGE DEPENDENCY OF ESSENTIAL FATTY-ACIDS IN CORD PLASMA-CHOLESTEROL ESTERS AND TRIGLYCERIDES

    NARCIS (Netherlands)

    HOVING, EB; VANBEUSEKOM, CM; NIJEBOER, HJ; MUSKIET, FAJ

    Plasma cholesterol ester and triglyceride fatty acid compositions of 38 singleton deliveries (23-42 wk), three twins (32, 39, and 40 wk), and their mothers were investigated. No gestational age-dependent changes occurred in maternal fatty acid compositions. Long-chain polyunsaturated fatty acids in

  17. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  18. Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2016-12-01

    Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

  19. Temperature dependence of the dielectric permittivity of acetic acid, propionic acid and their methyl esters: a molecular dynamics simulation study.

    Science.gov (United States)

    Riniker, Sereina; Horta, Bruno A C; Thijssen, Bram; Gupta, Saumya; van Gunsteren, Wilfred F; Hünenberger, Philippe H

    2012-04-10

    For most liquids, the static relative dielectric permittivity is a decreasing function of temperature, because enhanced thermal motion reduces the ability of the molecular dipoles to orient under the effect of an external electric field. Monocarboxylic fatty acids ranging from acetic to octanoic acid represent an exception to this general rule. Close to room temperature, their dielectric permittivity increases slightly with increasing temperature. Herein, the causes for this anomaly are investigated based on molecular dynamics simulations of acetic and propionic acids at different temperatures in the interval 283-363 K, using the GROMOS 53A6(OXY) force field. The corresponding methyl esters are also considered for comparison. The dielectric permittivity is calculated using either the box-dipole fluctuation (BDF) or the external electric field (EEF) methods. The normal and anomalous temperature dependences of the permittivity for the esters and acids, respectively, are reproduced. Furthermore, in the EEF approach, the response of the acids to an applied field of increasing strength is found to present two successive linear regimes before reaching saturation. The low-field permittivity ε, comparable to that obtained using the BDF approach, increases with increasing temperature. The higher-field permittivity ε' is slightly larger, and decreases with increasing temperature. Further analyses of the simulations in terms of radial distribution functions, hydrogen-bonded structures, and diffusion properties suggest that increasing the temperature or the applied field strength both promote a relative population shift from cyclic (mainly dimeric) to extended (chain-like) hydrogen-bonded structures. The lower effective dipole moment associated with the former structures compared to the latter ones provides an explanation for the peculiar dielectric properties of the two acids compared to their methyl esters. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Study of UltraHigh Performance Supercritical Fluid Chromatography to measure free fatty acids with out fatty acid ester preparation.

    Science.gov (United States)

    Ashraf-Khorassani, M; Isaac, G; Rainville, P; Fountain, K; Taylor, L T

    2015-08-01

    Most lipids are best characterized by their fatty acids which may differ in (a) chain length, (b) degree of unsaturation, (c) configuration and position of the double bonds, and (d) the presence of other functionalities. Thus, a fast, simple, and quantitative analytical technique to determine naturally occurring free fatty acids (FFA) in different samples is very important. Just as for saponified acylglycerols, the determination of FFA's has generally been carried out by high resolution gas chromatography (HRGC). The use of an open tubular capillary column coupled with a flame ionization or mass spectrometric detector provides for both high resolution and quantification of FFA's but only after conversion of all free fatty acids to fatty acid methyl esters (FAME) or pentafluorobenzyl esters. Unfortunately, volatilization of labile ester derivatives of mono- and poly-unsaturated FFA's can cause both thermal degradation and isomerization of the fatty acid during HRGC. The employment of a second generation instrument (here referred to as UltraHigh Performance Supercritical Fluid Chromatograph, UHPSFC) with high precision for modified flow and repeated back pressure adjustment in conjunction with sub-2μm various bonded silica particles (coupled with evaporative light scattering, ELSD, and mass spectrometric, MS, detection) for separation and detection of the following mixtures is described: (a) 31 free fatty acids, (b) isomeric FFA's, and (c) lipophilic materials in two real world fish oil samples. Limits of detection for FFA's via UHPSFC/MS and UHPSFC/ELSD versus detection of FAME's via HRGC/MS are quantitatively compared. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Enhancing the Acylation Activity of Acetic Acid by Formation of an Intermediate Aromatic Ester.

    Science.gov (United States)

    Duong, Nhung N; Wang, Bin; Sooknoi, Tawan; Crossley, Steven P; Resasco, Daniel E

    2017-07-10

    Acylation is an effective C-C bond-forming reaction to condense acetic acid and lignin-derived aromatic compounds into acetophenones, valuable precursors to fuels and chemicals. However, acetic acid is intrinsically an ineffective acylating agent. Here, we report that its acylation activity can be greatly enhanced by forming intermediate aromatic esters directly derived from acetic acid and phenolic compounds. Additionally, the acylation reaction was studied in the liquid phase over acid zeolites and was found to happen in two steps: 1) formation of an acylium ion and 2) C-C bond formation between the acylium ion and the aromatic substrate. Each of these steps may be rate-limiting, depending on the type of acylating agent and the aromatic substrate. Oxygen-containing substituents, such as -OH and -OCH3 , can activate aromatic substrates for step 2, with -OH> -OCH3 , whereas alkyl substituent -R cannot. At the same time, aromatic esters can rearrange to acetophenones by both an intramolecular pathway and, preferentially, an intermolecular one. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Metal-Free Domino One-Pot Decarboxylative Cyclization of Cinnamic Acid Esters: Synthesis of Functionalized Indanes.

    Science.gov (United States)

    Gopi Krishna Reddy, Alavala; Satyanarayana, Gedu

    2016-12-16

    Trifluoroacetic acid promoted unprecedented domino reaction for the synthesis of diverse indanes starting from simple cinnamic acid esters is described. Their formation can be explained via acid triggered decarboxylation of cinnamic acid esters and subsequent inter/intramolecular cyclization. Overall process involves in the intramolecular cleavage of two σ-bonds (C-O and C-C) and inter/intramolecular construction of two/one C-C σ-bond(s). Significantly, this protocol was successful without the aid of any metal salts.

  3. 21 CFR 582.4101 - Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat...

    Science.gov (United States)

    2010-04-01

    ... diglycerides of edible fats or oils, or edible fat-forming fatty acids. 582.4101 Section 582.4101 Food and... Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or edible fat-forming fatty acids. (a) Product. Diacetyl tartaric acid esters of mono- and diglycerides of edible fats or oils, or...

  4. Improved homopolymer separation to enable the application of H-1 NMR and HPLC for the determination of the reaction parameters of the graft copolymerization of acrylic acid onto starch

    NARCIS (Netherlands)

    Witono, Judy R.; Marsman, Jan Henk; Noordergraaf, Inge-Willem; Heeres, Hero J.; Janssen, Leon P. B. M.

    2013-01-01

    Graft copolymers of starch with acrylic acid are a promising green, bio based material with many potential applications. The grafting of acrylic acid onto cassava starch in an aqueous medium initiated by Fenton's reagent has been studied. Common grafting result parameters are add-on (yield) and

  5. Poly(acrylic acid) grafted montmorillonite as novel fillers for dental adhesives: synthesis, characterization and properties of the adhesive.

    Science.gov (United States)

    Solhi, Laleh; Atai, Mohammad; Nodehi, Azizollah; Imani, Mohammad; Ghaemi, Azadeh; Khosravi, Kazem

    2012-04-01

    This work investigates the graft polymerization of acrylic acid onto nanoclay platelets to be utilized as reinforcing fillers in an experimental dental adhesive. Physical and mechanical properties of the adhesive and its shear bond strength to dentin are studied. The effect of the modification on the stability of the nanoparticle dispersion in the dilute adhesive is also investigated. Poly(acrylic acid) (PAA) was grafted onto the pristine Na-MMT nanoclay (Cloisite(®) Na(+)) through the free radical polymerization of acylic acid in an aqueous media. The resulting PAA-g-nanoclay was characterized using FTIR, TGA and X-ray diffraction (XRD). The modified nanoclays were added to an experimental dental adhesive in different concentrations and the morphology of the nanoclay layers in the photocured adhesive matrix was studied using TEM and XRD. Shear bond strength of the adhesives containing different filler contents was tested on the human premolar teeth. The stability of nanoclay dispersion in the dilute adhesive was also studied using a separation analyzer. The results were then statistically analyzed and compared. The results confirmed the grafting reaction and revealed a partially exfoliated structure for the PAA-g-nanoclay. Incorporation of 0.2 wt.% of the modified nanoclay into the experimental adhesive provided higher shear bond strength. The dispersion stability of the modified nanoparticles in the dilute adhesive was also enhanced more than 25 times. Incorporation of the modified particles as reinforcing fillers into the adhesive resulted in higher mechanical properties. The nanofiller containing bonding agent also showed higher shear bond strength due to the probable interaction of the carboxylic acid functional groups on the surface of the modified particles with hydroxyapatite of dentin. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Study of the Transformation of the Oil of Used Soya in Fatty Acid Ethyl Ester

    Directory of Open Access Journals (Sweden)

    Anabel Sarracent-López

    2016-07-01

    Full Text Available The reuse of vegetable oils in food processing brings harmful health effects and on the other hand needs a complex treatment to discard without affecting the environment. Transformed into methyl or ethyl esters of fatty acids and glycerin by transesterification with the corresponding alcohol, can be a suitable method for treatment. It was investigated residual soybean oil from a producer of fried foods and ethanol. It is known that with this spirit the transformation process presents difficulties not listed with methanol, but at the same time does not bring the drawbacks of the latter, for toxicity and acquisition, and that since it is a derivative of the domestic sugar industry does not constitute a raw material import. We experimented with ethanol 80 %, 85 % and 90 % purity and worked 35 ºC and 50 ºC. Final yields of ethyl esters, are low compared with those obtained for similar processes with methanol, 85 % being the highest yield obtained under the conditions of the process. An assessment of costs was conducted to produce 1L of ethyl esters in the laboratory, the expenses of 0,56 pesos/L.

  7. Enantioselective Hydrolysis of Amino Acid Esters Promoted by Bis(β-cyclodextrin) Copper Complexes

    Science.gov (United States)

    Xue, Shan-Shan; Zhao, Meng; Ke, Zhuo-Feng; Cheng, Bei-Chen; Su, Hua; Cao, Qian; Cao, Zhen-Kun; Wang, Jun; Ji, Liang-Nian; Mao, Zong-Wan

    2016-02-01

    It is challenging to create artificial catalysts that approach enzymes with regard to catalytic efficiency and selectivity. The enantioselective catalysis ranks the privileged characteristic of enzymatic transformations. Here, we report two pyridine-linked bis(β-cyclodextrin) (bisCD) copper(II) complexes that enantioselectively hydrolyse chiral esters. Hydrolytic kinetic resolution of three pairs of amino acid ester enantiomers (S1-S3) at neutral pH indicated that the “back-to-back” bisCD complex CuL1 favoured higher catalytic efficiency and more pronounced enantioselectivity than the “face-to-face” complex CuL2. The best enantioselectivity was observed for N-Boc-phenylalanine 4-nitrophenyl ester (S2) enantiomers promoted by CuL1, which exhibited an enantiomer selectivity of 15.7. We observed preferential hydrolysis of L-S2 by CuL1, even in racemic S2, through chiral high-performance liquid chromatography (HPLC). We demonstrated that the enantioselective hydrolysis was related to the cooperative roles of the intramolecular flanking chiral CD cavities with the coordinated copper ion, according to the results of electrospray ionization mass spectrometry (ESI-MS), inhibition experiments, rotating-frame nuclear Overhauser effect spectroscopy (ROESY), and theoretical calculations. Although the catalytic parameters lag behind the level of enzymatic transformation, this study confirms the cooperative effect of the first and second coordination spheres of artificial catalysts in enantioselectivity and provides hints that may guide future explorations of enzyme mimics.

  8. Methyl Ester Production via Heterogeneous Acid-Catalyzed Simultaneous Transesterification and Esterification Reactions

    Science.gov (United States)

    Indrayanah, S.; Erwin; Marsih, I. N.; Suprapto; Murwani, I. K.

    2017-05-01

    The heterogeneous acid catalysts (MgF2 and ZnF2) have been used to catalyze the simultaneous transesterification and esterification reactions of crude palm oil (CPO) with methanol. Catalysts were synthesized by sol-gel method (combination of fluorolysis and hydrolysis). The physicochemical, structural, textural, thermal stability of the prepared catalysts was investigated by N2 adsorption-desorption, XRD, FT-IR, SEM and TG/DTG. Both MgF2 and ZnF2 have rutile structures with a different phase. The surface area of ZnF2 is smaller than that of MgF2, but the pore size and volume of ZnF2 are larger than those of MgF2. However, these materials are thermally stable. The performance of the catalysts is determined from the yield of catalysts toward the formation of methyl ester determined based on the product of methyl ester obtained from the reaction. The catalytic activity of ZnF2 is higher than MgF2 amounted to 85.21% and 26.82% with the optimum condition. The high activity of ZnF2 could be attributed to its pore diameter and pore volume but was not correlated with its surface area. The yield of methyl ester decreased along with the increase in molar ratio of methanol/CPO from 85.21 to 80.99 for ZnF2, respectively.

  9. The sensitizing potential of 2-ethylhexyl acrylate in the guinea pig.

    Science.gov (United States)

    Waegemaekers, T H; van der Walle, H B

    1983-09-01

    The sensitizing potential of 2-ethylhexyl acrylate in the guinea pig could be demonstrated by Freund's Complete Adjuvant Test. This acrylate ester is a common constituent of adhesive tape. Allergic reactions to several brands of adhesive tape were not observed in 2-ethylhexyl acrylate sensitized animals. Cross reactions with other acrylic monomers were observed.

  10. Chemo-enzymatic epoxidation of olefins by carboxylic acid esters and hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Ruesch gen. Klaas, M.; Warwel, S. [Inst. for Biochemistry and Technology of Lipids, H.P. Kaufmanm-Inst., Federal Centre for Cereal, Potato and Lipid Research, Muenster (Germany)

    1998-12-31

    Ethylen and, recently, butadiene can be epoxidized directly with oxygen and for the epoxidation of propylene, the use of heterogeneous transition metals and organic peroxides (Halcon-Process) is the major player. But, beside from those notable exceptions, all other epoxidations, including large ones like the epoxidation of plant oils as PVC-stabilizers (about 200.000 t/year), are carried out with peroxy acids. Because mcpba is far to expensive for most applications, short chain peracids like peracetic acid are used. Being much less stable than mcpba and thus risky handled in large amounts and high concentrations, these peroxy acids were preferably prepared in-situ. However, conventional in-situ formation of peracids has the serious drawback, that a strong acid is necessary to catalyze peroxy acid formation from the carboxylic acid and hydrogen peroxide. The presence of a strong acid in the reaction mixture often results in decreased selectivity because of the formation of undesired by-products by opening of the oxirane ring. Therefore, we propose a new method for epoxidation based on the in-situ preparation of percarboxylic acids from carboxylic acid esters and hydrogen peroxide catalyzed by a commercial, immobilized lipase. (orig.)

  11. Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

    KAUST Repository

    Batool, Farhat

    2016-11-18

    Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

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

    Science.gov (United States)

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

    2013-01-30

    Biodegradable films were produced from blends contained a high amount of thermoplastic starch (TPS) and poly(lactic acid) (PLA) plasticized with different adipate or citrate esters. It was not possible to obtain pellets for the production of films using only glycerol as a plasticizer. The plasticization of the PLA with the esters and mixture stages added through extrusion was critical to achieve a blend capable of producing films by blow extrusion. Adipate esters were the most effective plasticizers because they interacted best with the PLA and yielded films with appropriate mechanical properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    Al-Horani, Rami A; Desai, Umesh R

    2012-02-25

    Recent work in our laboratory has shown that the highly substituted, electronically rich 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (THIQ3CA) scaffold is a key building block for a novel class of promising anticoagulants (Al-Horani et al. J. Med. Chem.2011, 54, 6125-6138). The synthesis of THIQ3CA analogs, especially containing specific, electronically rich substituents, has been a challenge and essentially no efficient methods have been reported in the literature. We describe three complementary, glycine donor-based strategies for high yielding synthesis of highly substituted, electronically rich THIQ3CA esters. Three glycine donors studied herein include hydantoin 1, (±)-Boc-α-phosphonoglycine trimethyl ester 2 and (±)-Z-α-phosphonoglycine trimethyl ester 3. Although the synthesis of THIQ3CA analogs could be achieved using either of the three, an optimal, high yielding approach for the desired THIQ3CA esters was best achieved using 3 in three mild, efficient steps. Using this approach, a focused library of advanced N-arylacyl, N-arylalkyl, and bis-THIQ3CA analogs was synthesized. Variable temperature and solvent-dependent NMR chemical shift studies indicated the presence of two major conformational rotamers in 3:1 proportion for N-arylacyl-THIQ3CA analogs, which were separated by a high kinetic barrier of ~17 kcal/mol. In contrast, N-arylalkyl and bis-THIQ3CA variants displayed no rotamerism, which implicates restricted rotation around the amide bond as the origin for high-barrier conformational interconversion. This phenomenon is of major significance because structure-based drug design typically utilizes only one conformation. Overall, the work presents fundamental studies on the synthesis and conformational properties of highly substituted, electronically rich THIQ3CA analogs.

  14. Effects of fatty acid glycerol esters on intestinal absorptive and secretory transport of ceftibuten.

    Science.gov (United States)

    Koga, K; Murakami, M; Kawashima, S

    1999-04-01

    The effects of fatty acid glycerol esters and Tweens on the intestinal transport of ceftibuten were studied using a diffusion chamber system. The apparent permeation coefficient (P(app)) was used as an index of the mucosal permeability to ceftibuten. The P(app) markedly increased by the addition of hexaglycerol monostearate (HGMS) or hexaglycerol sesquistearate (HGSS) under an H+-gradient condition, while hexaglycerol tristearate (HGTS) and Tweens showed no effect on the absorptive ceftibuten permeability. These results are in agreement with those obtained in the previous study in the brush-border membrane vesicles. On the other hand, in the absence of an H+-gradient, the S-to-M transport of ceftibuten was proven to be significantly higher than the M-to-S one. In addition, either ATP-depletion of the mucosa or the addition of probenecid proved to enhance significantly the permeability of ceftibuten. These findings suggest the existence of an active secretory transport system for ceftibuten in the jejunal mucosa. To estimate potential effects of glycerol esters on efflux pumps as well as peptide transporters, the mucosal-to-serosal (M-to-S) and serosal-to-mucosal (S-to-M) permeability in the presence of the esters was further examined. HGMS, HGSS and HGTS markedly enhanced the M-to-S but not the S-to-M transport in the ATP-depleted jejunum without an H+-gradient, in which conditions contributions of both peptide transporter and efflux pump should be substantially small. HGMS and HGSS significantly enhanced the M-to-S ceftibuten transport in the ATP-depleted jejunum with an H+-gradient (pceftibuten due to the glycerol esters may be based on their effects on peptide transporters but neither on efflux pumps nor on the passive permeation routes.

  15. Synthesis and characterization of phosphonate ester and phosphonic acid containing polymers and blends

    Science.gov (United States)

    Tamber, Harinder Singh

    1997-12-01

    Vinylbenzylphosphonate ester (VBP) was homopolymerized and copolymerized with methyl methacrylate and the reactivity ratio of this pair of monomers was calculated from Finneman-Ross and Kelen-Tudos methods. These methods provided identical values, which are rsb1 (VBP) = 1.23 and rsb2(MMA) = 0.43. The phosphonate ester group, -P = O(OEt)sb2; in VBP and poly(VBP-MMA) copolymers was hydrolysed to phosphonic acid, -P = O(OH)sb2; at room temperature to obtain vinylbenzylphosphonic acid (VBPa) and poly(VBPa-MMA) copolymers. sp1H, sp{13}C & sp{31}P NMR spectroscopy, DSC and FTIR were used to monitor the hydrolysis of these phosphorylated monomers and polymers. The glass transition temperature of PVBP was 13sp°C as compared to 198sp°C of PVBPa. The phosphoryl group in the parent polymers acts as a self plasticizing agent resulting in lower glass transition temperature, on the other hand inter and intra hydrogen bonding results in broad and high Tsbg in these hydrolysed polymers. VBP was also polymerized with BisGMA or TEGDM to low conversions. These oligomers were tested in vitro as potential adhesive materials for dental/enamel and composite resins. The phosphonate esters containing polymers show substantial capacity to dissolve the heavy metal salts, e.g., UOsb2(NO)sb3.6Hsb2O and thus provides radiopaque polymers. Excessive sorption of water lead to phase separation and, hence, loss of radiopacity. Thus, an alternate method of synthesis of radiopaque polymers is also described in which radiopacifying agent is covalently linked to polymer backbone. Styryldiphenylbismuth was prepared by the reaction of diphenylbismuthchloride and Grignard of p-bromostyrene, but some other by-products such as triphenylbismuth, distyrylphenyl bismoth were also obtained as revealed by reverse phase HPLC and the yield of the reaction was low. Iodinated monomers VBTIsb3 and IEMIsb3 were prepared by reacting VBC or IEM to triiodophenol in high yields. Decomposition kinetic analysis was done by

  16. Preparation and drug-loading properties of Fe{sub 3}O{sub 4}/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wensheng [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China); Shen, Yuhua, E-mail: s_yuhua@163.com [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Xie, Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Zhang, Weiqiang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China)

    2013-11-15

    Fe{sub 3}O{sub 4}/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe{sub 3}O{sub 4} nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50–120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe{sub 3}O{sub 4} nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  17. Development of a New Environment-conscious Transformer Impregnated with Palm Fatty Acid Ester (PFAE)

    Science.gov (United States)

    Hikosaka, Tomoyuki; Yamazaki, Akina; Hatta, Yasunori; Koide, Hidenobu; Kanoh, Takaaki; Suzuki, Takashi; Yamada, Junichi; Uemura, Shingo

    We have developed a new environment-conscious transformer impregnated with vegetable based insulating oil which called PFAE (Palm Fatty Acid Ester). PFAE has 0.6 times less viscosity and 1.3 times higher dielectric constant compared to mineral oil. This means that a PFAE immersed transformer has better cooling efficiency and better insulating performance in paper-and-oil composite insulation systems, resulting in size reduction in comparison to conventional mineral oil immersed transformers. In this paper, insulating performance of lead to plane electrode models, cooling performance of a PFAE immersed transformer, and the result of analytical study of dissolved gas for abnormal diagnosis are described.

  18. Protective Effects of Caffeic Acid Phenethyl Ester on Cyclophosphamide-Induced Hemorrhagic Cystitis in Rats.

    Science.gov (United States)

    Uysal, Ersin; Yılmaz, H Ramazan; Ugan, Yunus; Altuntas, Atila; Dogru, Atalay; Kutlucan, Ali; Tunc, Sevket Ercan

    2015-12-01

    We investigated the protective effect of caffeic acid phenethyl ester (CAPE) on cyclophosphamide-induced hemorrhagic cystitis in rats in comparison with 2-mercaptoethane sulfonate (MESNA). Forty male rats were randomized into four groups: group 1 (control), group 2 (cyclophosphamide), group 3 (cyclophosphamide + MESNA), group 4 (cyclophosphamide + CAPE). Cyclophosphamide injection increased malondialdehyde levels indicating oxidative stress, whereas CAPE and MESNA ameliorated malondialdehyde levels in the bladder (p hemorrhagic cystitis, we suggest that it would be more beneficial to use MESNA with CAPE to prevent histological damage. © 2015 Wiley Periodicals, Inc.

  19. Can propolis and caffeic acid phenethyl ester (CAPE be promising agents against cyclophosphamide toxicity?

    Directory of Open Access Journals (Sweden)

    Sumeyya Akyol

    2016-03-01

    Full Text Available Propolis is a mixture having hundreds of polyphenols including caffeic acid phenethyl ester (CAPE. They have been using in several medical conditions/diseases in both in vitro and in vivo experimental setup. Cyclophosphamide has been used to treat a broad of malignancies including Hodgkin's and non-Hodgking's lymphoma, Burkitt's lymphoma, chronic lymphocytic leukemia, Ewing's sarcoma, breast cancer, testicular cancer, etc. It may cause several side effects after treatment. In this mini review, the protective effects of propolis and CAPE were compared each other in terms of effectiveness against cyclophosphamide-induced injuries. [J Intercult Ethnopharmacol 2016; 5(1.000: 105-107

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

    Directory of Open Access Journals (Sweden)

    Martin J. G. Hébert

    2015-01-01

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

  1. Nail psoriasis improvement in a patient treated with fumaric acid esters.

    Science.gov (United States)

    Vlachou, Christina; Berth-Jones, John

    2007-01-01

    Nail psoriasis is common in adult psoriatic patients and it causes serious psychological and physical distress. Topical treatments such as corticosteroids, calcipotriol, retinoids, and 5-fluorouracil have limited efficacy and are not without side effects. Relative effective systemic treatments are ciclosporin, methotrexate and acitretin, all of which have a serious toxicity potential. Biologics in the treatment of nail psoriasis have been the subject of recent research, but their cost-effectiveness is questionable. We present a case of psoriatic nail disease which improved greatly on treatment with fumaric acid esters (FAE).

  2. Radioimmunoassay for anileridine, meperidine, and other N-substituted phenylpiperidine carboxylic acid esters

    Energy Technology Data Exchange (ETDEWEB)

    Van Vunakis, H.; Freeman, D.S.; Gjika, H.B.

    1975-10-01

    Antibodies that bind an /sup 125/I-tyramyl derivative of N-succinylanileridine have been produced in animals immunized with N-succinylanileridine-hemocyanin conjugate. Several congeners and metabolites have been tested as competitors of this antigen-antibody reaction. The concentrations (in picomoles) required for 50 percent inhibition have been found to be: anileridine (0.2), meperidine (3.5), piminodine (3.8), diphenoxylate (20.5), normeperidine (20.0), meperidine acid (45,000) and anileridine acid (3,400). Although ester hydrolysis results in changes in inhibiting capacities on the order of 10/sup 4/, major structural changes in the substituent on the nitrogen of the piperidine ring are not readily recognized by the antibody. This radioimmunoassay can be used to study a variety of N-substituted phenylpiperidine carboxylic acid esters by relating the results to the standard curve obtained for the drug under investigation. For all practical purposes, alphaprodine, morphine and methadone do not interfere with the assay.

  3. One-Pot Synthesis of Highly Substituted Nicotinic Acid Derivatives Based on a Formylation Strategy of Enamino Keto Esters.

    Science.gov (United States)

    Kumar, Sukeerthi; Sawant, Aarti A; Chikhale, Rajendra P; Karanjai, Keya; Thomas, Abraham

    2016-02-19

    A facile one-pot synthesis of 4-chloro or 4-bromonicotinic acid esters with optional 2- and 2,5-disubstitution on the pyridine ring has been developed from easily accessible enamino keto esters by a formylation followed by in situ intramolecular cyclization strategy under optimized Vilsmeier reaction conditions. The effect of the substituents on the β-carbon and the nature of the keto functionality were explored in detail to understand the mechanism of pyridine ring formation under the described conditions.

  4. Controlled Release of Indomethacin from Smart Starch-Based Hydrogels Prepared Acrylic Acid and b-Cyclodextrin as a Nanocarrier

    Directory of Open Access Journals (Sweden)

    Hossein Ghasemzadeh Mohammadi

    2017-01-01

    Full Text Available Controlled release of drugs can reduce the undesired effects of drug level fluctuations, and diminish the side effects as well as improve the therapeutic outcome of the drugs. In recent year, the scope of the drug delivery systems has been greatly expanded by the development of various hydrogels. The present work has focused on the design of a pH sensitive drug delivery system (DDS based on starch, acrylic acid (AA and β-cyclodextrins for controlled delivery of indomethacin. The hydrogels were prepared via graft polymerization of acrylic acid (AA onto starch and β-cyclodextrins backbones by a free radical polymerization technique. Cyclodextrins are able to form water-soluble complexes with many lipophilic water-insoluble drugs. In aqueous solutions, the drug molecules located in the central cavity of the cyclodextrin are in a dynamic equilibrium with free drug molecules. The interaction of drug with the polymer was evidenced by FTIR spectroscopy and thermal gravimetric analysis (TGA. The morphology of the samples was examined by scanning electron microscopy (SEM. The results showed that the hydrogels have good porosity and provided high surface area for the loading and release of drugs. Drug release behavior was carried out at physiological conditions of phosphate buffer, pH 8. In basic pH (like the intestine medium the hydrogels released the indomethacin, but in acidic pH (like the stomach medium there was no tendency to drug release. By increasing the amount of cyclodextrin, the rate of drug loading and release increased due to the dynamic equilibrium and interaction between the loaded drug and the cyclodextrin. This study has demonstrated that the hydrogel matrices are potentially suitable for controlled-release systems.

  5. Phosphoric acid esters cannot replace polyvinylphosphonic acid as phosphoprotein analogs in biomimetic remineralization of resin-bonded dentin.

    Science.gov (United States)

    Mai, Sui; Kim, Young Kyung; Toledano, Manuel; Breschi, Lorenzo; Ling, Jun Qi; Pashley, David H; Tay, Franklin R

    2009-10-01

    Polyvinylphosphonic acid (PVPA), a biomimetic analog of phosphoproteins, is crucial for recruiting polyacrylic acid (PAA)-stabilized amorphous calcium phosphate nanoprecursors during biomimetic remineralization of dentin collagen matrices. This study tested the null hypothesis that phosphoric acid esters of methacrylates in dentin adhesives cannot replace PVPA during bimimetic remineralization of resin-dentin interfaces. Human dentin specimens were bonded with: (I) XP Bond, an etch-and-rinse adhesive using moist bonding; (II) XP Bond using dry bonding; (III) Adper Prompt L-Pop, a self-etching adhesive. The control medium contained only set Portland cement and a simulated body fluid (SBF) without any biomimetic analog. Two experimental Portland cement/SBF remineralization media were evaluated: the first contained PAA as the sole biomimetic analog, the second contained PAA and PVPA as dual biomimetic analogs. No remineralization of the resin-dentin interfaces could be identified from specimens immersed in the control medium. After 2-4 months in the first experimental medium, specimens exhibited either no remineralization or large crystal formation within hybrid layers. Only specimens immersed in the second remineralization medium produced nanocrystals that accounted for intrafibrillar remineralization within hybrid layers. The null hypothesis could not be rejected; phosphoric acid esters in dentin adhesives cannot replace PVPA during biomimetic remineralization of adhesive-bonded dentin.

  6. Lower critical solution temperature behavior of alpha-substituted poly(acrylic acids)s, cyclopolymerization of N-vinylformamido-methylacrylates, and use of the World-Wide Web in polymer science education

    Science.gov (United States)

    Michalovic, Mark Stephen

    A series of alpha-substituted poly(acrylic acid)s was synthesized and characterized. Their aqueous solution properties were investigated with respect to lower critical solution temperature (LCST) behavior. Poly(alpha-methoxymethylacrylic acid) was found to have a lower critical solution temperature (LCST) of 46°C, poly(alpha-methoxyethoxymethylacrylic acid) showed an LCST of 26.5°C and poly(alpha-methoxyethoxyethoxymethylacrylic acid) showed an LCST of 66°C. The cloud points of the solutions of these polymers were found to be sensitive to pH, and to concentrations of additives such as urea, salts, and surfactants. Because of low molecular weight due to chain transfer, high molecular weight analogs of the ether-linked polymers were synthesized in which ester linkages joined the oligo-oxyethylene segment to the acrylate moiety. Poly(alpha-methoxyethoxyacetoxymethylacrylic acid) was the only one of this series to give an LCST with a value of 52.5°C. Copolymers of t-butyl alpha-methoxymethylacrylate (tBMMA) with alpha-(1H,1H- perfluorooctyloxymethyl)acrylic acid (PFOMA) were synthesized, deprotected and their lower critical solution temperatures (LCSTs) evaluated. At PFOMA feed ratios of 0.25 mol % or less, no observable change in the LCST was observed, while at PFOMA feed ratios of above 0.25 mol % to 1.125 mol %, a large linear decrease in the LCST was observed with increasing fluorocarbon content. t-Butyl alpha-(N-vinylformamidomethyl)acrylate (tBVFA) and ethyl alpha-(N-vinylformamidomethyl)acrylate (EVFA) were synthesized from t-butyl alpha-bromomethylacrylate and ethyl alpha-chloromethylacrylate, respectively. tBVFA was found to cyclopolymerize at 120°C in DMF, DMSO, and 1,2-dichlorobenzene at solvent:monomer ratios of 10:1 vol:wt. Molecular weights for poly(tBVFA) ranged from 10,000 to 13,000 as estimated by size-exclusion chromatography. At lower solvent monomer ratio (1:1), and at lower temperature (71°C), crosslinking occurred. EVFA was found to

  7. One-Pot, Three-Step Synthesis of Cyclopropylboronic Acid Pinacol Esters from Synthetically Tractable Propargylic Silyl Ethers.

    Science.gov (United States)

    Spencer, Jonathan A; Jamieson, Craig; Talbot, Eric P A

    2017-07-21

    Simple propargylic silyl ethers can be converted to complex cyclopropylboronic acid pinacol esters in an efficient one-pot procedure. Terminal acetylenes undergo a Schwartz's reagent catalyzed hydroboration; subsequent addition of further Schwartz's reagent and Lewis acid-mediated activation of neighboring silyl ether allows cyclization to access a range of cyclopropylboronic acid pinacol esters. The scope includes aromatic, aliphatic, quaternary, and spiro substituted cyclopropyl rings, which can be transformed via Suzuki coupling into a range of lead-like substituted cyclopropyl aryl products.

  8. Graft copolymerization of acrylic acid to cassava starch-Evaluation of the influences of process parameters by an experimental design method

    NARCIS (Netherlands)

    Witono, J. R.; Noordergraaf, I. W.; Heeres, H. J.; Janssen, L. P. B. M.

    2012-01-01

    The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe2+/H2O2 redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this

  9. Detection system for Saccharomyces cerevisiae with phenyl acrylic acid decarboxylase gene (PAD1) and sulphur efflux gene (SSU1) by multiplex PCR.

    Science.gov (United States)

    Archana, K M; Anu-Appaiah, K A

    2017-10-16

    Production of wine with selected yeast strains is a common enological practice followed for the production of wine with desirable organoleptic properties and to guarantee the homogeneity of successive vintages. Sulphur dioxide tolerance and phenyl acrylic acid resistance are the enological traits essential for the survivability of the yeast during fermentation. The present study describes the detection of S. cerevisiae with enological traits, such as phenyl acrylic acid resistance and sulphur dioxide tolerance in a single test. Phenyl acrylic acid decarboxylase (PAD1) and sulphite efflux genes (SSU1) were detected by multiplex PCR, thus confirming the specificity of primers. A single cocktail of all reagents required for the simultaneous detection of both these genes was designed. The ready-to-use formulation optimized was stable at 4 and - 20 °C for 6 months. The amplification of phenyl acrylic acid decarboxylase and sulphite efflux genes, validated the suitability of the ready-to-use formulation for the detection of S. cerevisiae in food samples. The ready-to-use formulation optimized, minimizes the end user requirements for the detection of S. cerevisiae. Thus, the method was suitable for the identification of S. cerevisiae strains from a mixture of yeast prior to the sequencing analysis, thereby reducing the cost and time of screening.

  10. Chemically imaging the effects of the addition of nanofibrillated cellulose on the distribution of poly(acrylic acid) in poly(vinyl alcohol)

    Science.gov (United States)

    Craig Clemons; Julia Sedlmair; Barbara Illman; Rebecca Ibach; Carol Hirschmugl

    2013-01-01

    The distribution of poly(acrylic acid) (PAA) in model laminates of nanocellulose and poly(vinyl alcohol) (PVOH) was investigated by FTIR chemical imaging. The method was effective in spatially discerning the three components of the composite. PAA can potentially improve the performance of nanocellulose reinforced PVOH by not only crosslinking the PVOH matrix but also...

  11. In vivo and in vitro evaluation of the efficacy of a peracetic acid-based disinfectant for decontamination of acrylic resins.

    Science.gov (United States)

    Chassot, Ana Lúcia Campani; Poisl, Maria Inês Pereira; Samuel, Susana Maria Werner

    2006-01-01

    The purpose of this study was to assess the antimicrobial efficacy of a peracetic acid-based disinfectant for decontamination of heat-polymerized, chemically activated and microwave-polymerized acrylic resins. Resin plates were contaminated in vivo upon intraoral use by 10 volunteers for 7 nights and slabs were contaminated in vitro by contact with Bacillus subtilis and Bacillus stearothermophilus. The contaminated acrylic resin specimens were immersed in a 0.2% peracetic acid-based disinfectant (Sterilife; Lifemed) for 5 min or 10 min and placed in a BHI culture medium. After incubation at 37 degrees C for 48 h, bacterial growth was assessed by analyzing turbidity of the medium. For all types of acrylic resin, no turbidity of the medium was observed for any of the resin specimens immersed in the peracetic acid-based disinfectant for either 5 or 10 min. On the other hand, the media with specimens that were not immersed in the disinfectant (control) showed turbidity in 100% of the cases, indicating the presence of microorganisms in both tested conditions. In conclusion, immersion for at least 5 min in a 0.2% peracetic acid-based disinfectant promoted high-level disinfection of heat-polymerized, chemically activated and microwave-polymerized acrylic resins contaminated with either human saliva or Bacillus subtilis or Bacillus stearothermophilus.

  12. The use of dielectric spectroscopy for the characterisation of the precipitation of hydrophobically modified poly(acrylic-acid) with divalent barium ions

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2009-01-01

    The use of dielectric spectroscopy as a monitor for coagulation processes was investigated. Hydrophobically modified poly(acrylic-acid) polymers were used as model macromolecules and coagulated with barium ions. The coagulation process was quantified using a photometric dispersion analyser, thereby...

  13. A new coordination mode of (E)-3-(3-hydroxyl-phenyl)-acrylic acid in copper complex: Crystal structure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin; Zhou, Pei; Zheng, Chunying [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China); Li, Hui, E-mail: lihui@bit.edu [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China)

    2015-05-15

    A copper complex ([Cu(py){sub 2}(L){sub 2}]·2CH{sub 3}OH){sub n} (HL=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) (1) with acrylic acid ligand was synthesized and structurally analyzed by IR, elemental analysis, TGA and the single-crystal X-ray diffraction methods. It is the first time to find that phenolic hydroxyl of L coordinates to Cu(II). Complex 1 exhibits 1D chain by a double-bridge of ligands, and the 3D supramolecular framework in complex 1 is constructed by π–π stacking interactions and van der Waals Contacts among the 1D chains. The magnetic properties of complex 1 have been studied. - Graphical abstract: A copper complex based on (E)-3-(3-hydroxyl-phenyl)-acrylic acid in a novel coordinated way was synthesized and a ferromagnetic exchange interactions between neighboring Cu(II) ions has be achieved. - Highlights: • A new copper complex with acrylic acid ligand was synthesized and analyzed. • We find the phenolic hydroxyl of MCA ligand coordinates to metal ion firstly. • A ferromagnetic exchange interactions between Cu(II) ions has been achieved.

  14. Chloroindolyl-3-acetic Acid and its Methyl Ester Incorporation of 36Cl in Immature Seeds of Pea and Barley

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1974-01-01

    compounds besides Cl−. One compound, present in pea and probably in barley, cochromatographed with a mixture of 4- and 6-chloroindolyl-3-acetic acid methyl esters. Another, detected in pea, but probably not in barley, cochromatographed with a mixture of 4-and 6-chloroindolyl-3-acetic acids....

  15. A study on the swelling behavior of poly(acrylic acid) hydrogels obtained by electron beam crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Sheikh, N., E-mail: nasheikh@aeoi.org.i [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Jalili, L. [Polymer group, Technology and Engineering Department, Yazd University, Yazd (Iran, Islamic Republic of); Anvari, F. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Yazd (Iran, Islamic Republic of)

    2010-06-15

    Poly(acrylic acid) (PAA) hydrogels were prepared by using electron beam (EB) crosslinking of PAA homopolymer from its aqueous solutions. The swelling behavior of the hydrogels was studied as a function of the concentration of PAA solution, radiation dose, pH of the swelling medium and swelling time. Also the environmental pH effect on the water diffusion mode into hydrogels was investigated. These hydrogels clearly showed pH-sensitive swelling behavior with Fickian type of diffusion in the stomach-like pH medium (pH 1.3) and non-Fickian type in the intestine-like pH medium (pH 6.8).

  16. Thermoresponsive Photonic Crystal: Synergistic Effect of Poly(N-isopropylacrylamide)-co-acrylic Acid and Morpho Butterfly Wing.

    Science.gov (United States)

    Xu, Dongdong; Yu, Huanan; Xu, Qun; Xu, Guiheng; Wang, Kaixi

    2015-04-29

    In this work, we report a simple method to fabricate smart polymers engineered with hierarchical photonic structures of Morpho butterfly wing to present high performance that are capable of color tunability over temperature. The materials were assembled by combining functional temperature responsivity of poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAm-co-AAc) with the biological photonic crystal (PC) structure of Morpho butterfly wing, and then the synergistic effect between the functional polymer and the natural PC structure was created. Their cooperativity is instantiated in the phase transition of PNIPAm-co-AAc (varying with the change of temperature) that can alter the nanostructure of PCs, which further leads to the reversible spectrum response property of the modified hierarchical photonic structures. The cost-effective biomimetic technique presented here highlights the bright prospect of fabrication of more stimuli-responsive functional materials via coassembling smart polymers and biohierarchical structures, and it will be an important platform for the development of nanosmart biomaterials.

  17. Poly(acrylic acid)-directed synthesis of colloidally stable single domain magnetite nanoparticles via partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Altan, Cem L. [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Gurten, Berna [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sadza, Roel [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Yenigul, Elcin [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sommerdijk, Nico A.J.M., E-mail: n.sommerdijk@tue.nl [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Bucak, Seyda, E-mail: seyda@yeditepe.edu.tr [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey)

    2016-10-15

    Octahedral, single domain magnetite nanoparticles with average size of ~55 nm were synthesized through oxidative aging of a ferrous hydroxide (Fe(OH){sub 2}) precursor at high pH in water. The synthesis was also carried out in the presence of the hydrophilic polymer poly(acrylic acid). Presence of the polymer changed the particle morphology from octahedral to spherical while average size decreased to 40–50 nm. Although these particles have a tendency to precipitate due to their high magnetic moment, dispersions of these particles were obtained in the presence of this particular polymer which made the particles stable in water for several days making them suitable for various biotechnological applications such as cell separation owing to their low toxicity. - Highlights: • Stable, single domain magnetite nanoparticles are synthesized via partial oxidation. • Particles are readily stabilized in water by a biocompatible polymer. • Steric barrier is essential for the stabilization of large magnetite nanoparticles.

  18. Polydopamine-coated electrospun poly(vinyl alcohol)/poly(acrylic acid) membranes as efficient dye adsorbent with good recyclability.

    Science.gov (United States)

    Yan, Jiajie; Huang, Yunpeng; Miao, Yue-E; Tjiu, Weng Weei; Liu, Tianxi

    2015-01-01

    Free-standing poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) membranes with polydopamine (PDA) coating were prepared based on the combination of electrospinning and self-polymerization of dopamine. This is a facile, mild, controllable, and low-energy consumption process without any rigorous restriction to reactive conditions. Benefiting from the high specific surface area of electrospun membranes and the abundant "adhesive" functional groups of polydopamine, the as-prepared membranes exhibit efficient adsorption performance towards methyl blue with the adsorption capacity reaching up to 1147.6 mg g(-1). Moreover, compared to other nanoparticle adsorbents, the as-prepared self-standing membrane is highly flexible, easy to operate and retrieve, and most importantly, easy to elute, and regenerate, which enable its potential applications in wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Preparation and applications of novel fluoroalkyl end-capped acrylic acid oligomers/silica nanocomposites-encapsulated fullerenes.

    Science.gov (United States)

    Kasai, Remi; Yaegashi, Hideaki; Yokoyama, Hiroshi; Yamanaka, Masahiko; Sawada, Hideo

    2007-01-01

    Fluoroalkyl end-capped acrylic acid oligomers/fullerenes nanocomposites reacted smoothly with tetraethoxysilane (TEOS) and silica nanoparticles under alkaline conditions to give fluoroalkyl end-capped oligomers/silica composites-encapsulated fullerenes. Interestingly, these isolated fluorinated composites were found to afford nanometer size-controlled colloidal particles with a good dispersibility in a variety of organic solvents including water. More interestingly, these fluorinated silica nanocomposites-encapsulated fullerenes were applied to a new type of surface modification agent, and these nanocomposites were able to disperse well above the poly(methyl methacrylate) films to exhibit not only surface active property imparted by fluorine but also a unique characteristic related to fullerenes in the nanocomposites on the surface, effectively.

  20. BIODEGRADABLE PLASTICS FROM A MIXTURE OF LOW DENSITY POLYETHYLENE (LDPE AND CASSAVA STARCH WITH THE ADDITION OF ACRYLIC ACID

    Directory of Open Access Journals (Sweden)

    Susilawati Susilawati

    2013-05-01

    Full Text Available A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to  studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w  while tensile strength  equal to 0,38 Kgf/mm2.  SEM characterization showed that biodegradation has occurred by  formation of hole in the biodegradable plastic surface. DTA test gave Tg = 130 °C, Tm = 230 °C and Td = 370-450 °C while FT-IR analysis showed that the biodegradable plastics have a chemistry interaction.

  1. Cloning, Sequence Analysis, and Expression in Escherichia coli of the Gene Encoding an α-Amino Acid Ester Hydrolase from Acetobacter turbidans

    NARCIS (Netherlands)

    Polderman-Tijmes, Jolanda J.; Jekel, P; de Vries, Erik; van Merode, Annet; Floris, René; Laan, Jan-Metske van der; Sonke, Theo; Janssen, Dick B.

    The α-amino acid ester hydrolase from Acetobacter turbidans ATCC 9325 is capable of hydrolyzing and synthesizing β-lactam antibiotics, such as cephalexin and ampicillin. N-terminal amino acid sequencing of the purified α-amino acid ester hydrolase allowed cloning and genetic characterization of the

  2. Cloning, sequence analysis, and expression in Escherichia coli of the gene encoding an alpha-amino acid ester hydrolase from Acetobacter turbidans

    NARCIS (Netherlands)

    Polderman-Tijmes, JJ; Jekel, PA; de Vries, EJ; van Merode, Annet; Floris, R; van der Laan, JM; Sonke, T; Janssen, DB

    The alpha-amino acid ester hydrolase from Acetobacter turbidans ATCC 9325 is capable of hydrolyzing and synthesizing beta-lactam antibiotics, such as cephalexin and ampicillin. N-terminal amino acid sequencing of the purified alpha-amino acid ester hydrolase allowed cloning and genetic

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

    Science.gov (United States)

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

    2012-02-01

    An enzymatic reactor with lipase immobilized on a monolithic polymer support has been prepared and used to catalyze the transesterification of triacylglycerides into the fatty acid methyl esters commonly used for biodiesel. A design of experiments procedure was used to optimize the monolithic reactor with variables including control of the surface polarity of the monolith via variations in the length of the hydrocarbon chain in alkyl methacrylate monomer, time of grafting of 1-vinyl-4,4-dimethylazlactone used to activate the monolith, and time used for the immobilization of porcine lipase. Optimal conditions involved the use of a poly(stearyl methacrylate-co-ethylene dimethacrylate) monolith, grafted first with vinylazlactone, then treated with lipase for 2 h to carry out the immobilization of the enzyme. Best conditions for the transesterification of glyceryl tributyrate included a temperature of 37°C and a 10 min residence time of the substrate in the bioreactor. The reactor did not lose its activity even after pumping through it a solution of substrate equaling 1,000 reactor volumes. This enzymatic reactor was also used for the transesterification of triacylglycerides from soybean oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. Copyright © 2011 Wiley Periodicals, Inc.

  4. Radio-Modulatory Potential ofCaffeic Acid Phenethyl Ester: A Therapeutic Perspective.

    Science.gov (United States)

    Anjaly, Km; Tiku, Ashu

    2017-11-13

    Use of natural agents is an upcoming area of research in cancer biology. Caffeic acid phenethyl ester has received great attention because of its therapeutic potential in various conditions including cancer. It is an active/abundant component of propolis. Propolis is a honey bee hive product produced by bees using their enzyme-rich digestive secretions on resinous mix, bee wax and pollen from plants. It is used to protect the beehive against bacteria and other infections.Although a lot of work has been done on chemotherapeutic aspects of CAPE, its role as a radiomodulator is yet to be delineated. It can act both as radioprotector and radiosensitizer. Depending on the tissue type it can modulate the radiation response by following different mechanisms. This review will focus on the differential radiomodulatory effects of Caffeic Acid Phenethyl Ester in normal and cancer cells.Besides chemistry and bioavailability,it's potential as a therapeutic agent against radiation induced damage will also be discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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

    KAUST Repository

    Urban, Jiří T.

    2011-09-26

    An enzymatic reactor with lipase immobilized on a monolithic polymer support has been prepared and used to catalyze the transesterification of triacylglycerides into the fatty acid methyl esters commonly used for biodiesel. A design of experiments procedure was used to optimize the monolithic reactor with variables including control of the surface polarity of the monolith via variations in the length of the hydrocarbon chain in alkyl methacrylate monomer, time of grafting of 1-vinyl-4,4-dimethylazlactone used to activate the monolith, and time used for the immobilization of porcine lipase. Optimal conditions involved the use of a poly(stearyl methacrylate-co-ethylene dimethacrylate) monolith, grafted first with vinylazlactone, then treated with lipase for 2h to carry out the immobilization of the enzyme. Best conditions for the transesterification of glyceryl tributyrate included a temperature of 37°C and a 10min residence time of the substrate in the bioreactor. The reactor did not lose its activity even after pumping through it a solution of substrate equaling 1,000 reactor volumes. This enzymatic reactor was also used for the transesterification of triacylglycerides from soybean oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. © 2011 Wiley Periodicals, Inc.

  6. Alkyl esters of fatty acids a useful tool to detect soft deodorized olive oils.

    Science.gov (United States)

    Pérez-Camino, María del Carmen; Cert, Arturo; Romero-Segura, Ana; Cert-Trujillo, Rosa; Moreda, Wenceslao

    2008-08-13

    Fatty acid alkyl esters (FAAEs) are a family of natural neutral lipids present in olive oils and formed by esterification of free fatty acids (FFAs) with low molecular alcohols. Inappropriate practices during the olive oil extraction process and bad quality of the olive fruits promote their formation. Quantification can be done by isolation with a silica gel solid phase extraction cartridge followed by analysis on a gas chromatograph equipped with a programmed temperature vaporizer injector using a polar capillary column. The application of the method to more than 100 Spanish olive oils from different categories, varieties, and geographical origin allowed for establishing the average content of FAAEs and distinguishing the Spanish protected denomination of origin (PDO) and extra virgin olive oils from other categories of olive oils. Those other categories of oils can be subjected to a mild refining process, which leads to blending with extra virgin olive oils. Studies on low quality oils subjected to mild refining showed that FAAEs remain after that process. Thereby, blends of extra virgin olive and mildly refined low quality olive oils can be detected by their alkyl ester concentrations.

  7. Engineering and systems level analysis of Saccharomyces cerevisiae for production of 3 hydroxypropionic acid via malonyl CoA reductase dependent pathway

    DEFF Research Database (Denmark)

    Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg; Schneider, Konstantin

    2016-01-01

    In the future, oil- and gas-derived polymers may be replaced with bio-based polymers, produced from renewable feedstocks using engineered cell factories. Acrylic acid and acrylic esters with an estimated world annual production of approximately 6 million tons by 2017 can be derived from 3...

  8. Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels for pH-sensitive photocatalytic degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Young-E; Jung, Gowun; Yun, Jumi; Kim, Hyung-Il, E-mail: hikim@cnu.ac.kr

    2013-10-01

    Graphical abstract: The photocatalytic removal of pollutants was improved by the two-step mechanism based on the adsorption of pollutants by hydrogel and the effective decomposition by combination of TiO{sub 2} and graphene oxide. -- Highlights: • pH sensitive PVA/PAAc hydrogels were prepared by radical polymerization and condensation reaction. • PVA/PAAc/TiO{sub 2}/graphene oxide nanocomposite hydrogels were used for treatment of basic waste water. • Photocatalytic acitivity of TiO{sub 2} was improved by incorporation of graphene oxide. • Photocatalytic decomposition by nanocomposite hydrogel was improved by increasing pH. -- Abstract: Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were prepared using radical polymerization and condensation reaction for the photocatalytic treatment of waste water. Graphene oxide was used as an additive to improve the photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2} nanocomposite hydrogels. Both TiO{sub 2} and graphene oxide were immobilized in poly(vinyl alcohol)/poly(acrylic acid) hydrogel matrix for an easier recovery after the waste water treatment. The photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels was evaluated on the base of the degradation of pollutants by using UV spectrometer. The improved removal of pollutants was due to the two-step mechanism based on the adsorption of pollutants by nanocomposite hydrogel and the effective decomposition of pollutants by TiO{sub 2} and graphene oxide. The highest swelling of nanocomposite hydrogel was observed at pH 10 indicating that poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were suitable as a promising system for the treatment of basic waste water.

  9. Fatty acid ethyl ester synthesis in the preparation of scotch whiskey.

    Science.gov (United States)

    Goss, K A; Alharethi, R; Laposata, M

    1999-04-01

    Fatty acid ethyl esters (FAEE), nonoxidative ethanol metabolites present in human organs commonly damaged by ethanol abuse, have been implicated as mediators of organ damage. FAEE are additives in various foods and beverages to provide flavor or fragrance, and therefore are common dietary lipid constituents. We hypothesized that FAEE could be generated during alcoholic beverage production because fatty acids are present within microorganisms and ethanol is generated during the fermentation process. In this report, we demonstrate that FAEE are present in commercially available scotch beverages, and that in the preparation of scotch, FAEE can be produced during the fermentation reaction as a result of FAEE synthase activity in the yeast. Following ingestion of scotch, preformed FAEE are delivered to GI tract. The consequences of ingestion of FAEE in scotch, if any, remain to be determined.

  10. Preanalytical variables affecting the quantification of fatty acid ethyl esters in plasma and serum samples.

    Science.gov (United States)

    Soderberg, B L; Sicinska, E T; Blodget, E; Cluette-Brown, J E; Suter, P M; Schuppisser, T; Vetter, W; Laposata, M

    1999-12-01

    Fatty acid ethyl esters (FAEEs) are cytotoxic nonoxidative ethanol metabolites produced by esterification of fatty acids and ethanol. FAEEs are detectable in blood up to 24 h after ethanol consumption. The objective of this study was to assess the impact of gender, serum or plasma triglyceride concentration, time and temperature of specimen storage, type of alcoholic beverage ingested, and the rate of ethanol consumption on FAEE concentrations in plasma or serum. For some studies, subject were recruited volunteers; in others, residual blood samples after ethanol quantification were used. FAEEs were isolated by solid-phase extraction and quantified by gas chromatography-mass spectrometry. For weight-adjusted amounts of ethanol intake, FAEE concentrations were twofold greater for men than women (P /=24 h. The type of alcoholic beverage and rate of consumption did not affect FAEE concentrations. These studies advance plasma and serum FAEE measurements closer to implementation as a clinical test for ethanol intake.

  11. An Advanced TALSPEAK Concept Using 2-Ethylhexylphosphonic Acid Mono-2-Ethylhexyl Ester as the Extractant

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Casella, Amanda J.; Rapko, Brian M.; Levitskaia, Tatiana G.; Pence, Natasha K.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-12-21

    A method for separating the trivalent actinides and lanthanides is being developed using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) as the extractant. The method is based on the preferential binding of the actinides in the aqueous phase by N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), which serves to keep the actinides in the aqueous phase while the lanthanides are extracted into an organic phase containing HEH[EHP]. The process is very robust, showing little dependence upon the pH or the HEH[EHP], HEDTA, and citrate concentrations over the ranges that might be expected in a nuclear fuel recycling plant. Single-stage runs with a 2-cm centrifugal contactor indicate that modifications to the process chemistry may be needed to increase the extraction rate for Sm, Eu, and Gd. The hydraulic properties of the system are favorable to application in centrifugal contactors.

  12. Effects of fatty acid sucrose esters on ceftibuten transport by rat intestinal brush-border membrane vesicles.

    Science.gov (United States)

    Koga, K; Murakami, M; Kawashima, S

    1998-07-01

    The effects of fatty acid sucrose esters on membrane lipid dynamics and ceftibuten transport by rat intestinal brush-border membrane vesicles (BBMV) were examined to clarify the differences in the action of mono- and poly-acyl sucrose esters on the drug transport. Fatty acid sucrose mono-acyl ester (SS) inhibited ceftibuten transport by BBMV similar to the action of polyoxyethylene sorbitans (Tweens), while fatty acid sucrose polyacyl ester mixtures (F-160 and F-140) did not affect the drug transport by BBMV. SS but not F-160 and F-140 caused an increase in the anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH)- and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene iodide (TMA-DPH)-labeled BBMV in a concentration-dependent manner. Thus, the uptake of ceftibuten by BBMV was strongly correlated with the lipid fluidity of BBMV, in the outer layer and in the inner hydrophobic regions; however, there was no strong correlation between the membrane lipid fluidity and the drug uptake by BBMV. The micelle size and the size distribution of F-160 and F-140 were larger and more widely dispersed, respectively, compared to those of SS and Tweens. These results suggest that the effects of fatty acid sucrose esters on ceftibuten transport by BBMV are related to the dispersion parameter of these pharmaceutical adjuvants.

  13. RAFT-Mediated Polymerization-Induced Self-Assembly of Poly(Acrylic Acid-b-Poly(Hexafluorobutyl Acrylate: Effect of the pH on the Synthesis of Self-Stabilized Particles

    Directory of Open Access Journals (Sweden)

    Jianhua Zhou

    2016-05-01

    Full Text Available This paper describes a very simple strategy towards self-stabilized poly(acrylic acid-block-poly(hexafluorobutyl acrylate (PAA-b-PHFBA block copolymer particles via reversible addition-fragmentation chain transfer (RAFT-mediated polymerization-induced self-assembly. Hexafluorobutyl acrylate (HFBA monomer conversion and number-average molar mass of PAA-b-PHFBA increased gradually with the increase in the pH value of the aqueous phase. When pH < 10, the molecular weight distributions of PAA-b-PHFBA were narrow, however, when the pH was raised to 11.55, PAA-b-PHFBA block copolymers had a broader distribution (ĐM = 1.82 with a serious trailing toward the low molecular weight. Furthermore, the morphology and size of PAA-b-PHFBA latex particles were measured by transmission electron microscopy and dynamic light scattering. The results indicated that the PAA-b-PHFBA latex particles had a clear spherical core-shell structure and the latex particles’ size increased with the increase of pH value.

  14. Highly functionalized 1,2-diamino compounds through reductive amination of amino acid-derived β-keto esters.

    Directory of Open Access Journals (Sweden)

    Paula Pérez-Faginas

    Full Text Available 1,2-Diamine derivatives are valuable building blocks to heterocyclic compounds and important precursors of biologically relevant compounds. In this respect, amino acid-derived β-keto esters are a suitable starting point for the synthesis of β,γ-diamino ester derivatives through a two-step reductive amination procedure with either simple amines or α-amino esters. AcOH and NaBH(3CN are the additive and reducing agents of choice. The stereoselectivity of the reaction is still an issue, due to the slow imine-enamine equilibria through which the reaction occurs, affording mixtures of diastereoisomers that can be chromatographically separated. Transformation of the β,γ-diamino esters into pyrrolidinone derivatives allows the configuration assignment of the linear compounds, and constitutes an example of their potential application in the generation of molecular diversity.

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

    Science.gov (United States)

    Britton, Stephanie Lynne

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

  16. Selective catalytic oxidative-dehydrogenation of carboxylic acids-acrylate and crotonate formation at the Au/TiO2 interface.

    Science.gov (United States)

    McEntee, Monica; Tang, Wenjie; Neurock, Matthew; Yates, John T

    2014-04-02

    The oxidative-dehydrogenation of carboxylic acids to selectively produce unsaturated acids at the second and third carbons regardless of alkyl chain length was found to occur on a Au/TiO2 catalyst. Using transmission infrared spectroscopy (IR) and density functional theory (DFT), unsaturated acrylate (H2C═CHCOO) and crotonate (CH3CH═CHCOO) were observed to form from propionic acid (H3CCH2COOH) and butyric acid (H3CCH2CH2COOH), respectively, on a catalyst with ∼3 nm diameter Au particles on TiO2 at 400 K. Desorption experiments also show gas phase acrylic acid is produced. Isotopically labeled (13)C and (12)C propionic acid experiments along with DFT calculated frequency shifts confirm the formation of acrylate and crotonate. Experiments on pure TiO2 confirmed that the unsaturated acids were not produced on the TiO2 support alone, providing evidence that the sites for catalytic activity are at the dual Au-Ti(4+) sites at the nanometer Au particles' perimeter. The DFT calculated energy barriers between 0.3 and 0.5 eV for the reaction pathway are consistent with the reaction occurring at 400 K on Au/TiO2.

  17. Polystyrene-b-poly(tert-butyl acrylate) and polystyrene-b-poly(acrylic acid) dendrimer-like copolymers: two-dimensional self-assembly at the air-water interface.

    Science.gov (United States)

    Joncheray, Thomas J; Bernard, Sophie A; Matmour, Rachid; Lepoittevin, Bénédicte; El-Khouri, Rita J; Taton, Daniel; Gnanou, Yves; Duran, Randolph S

    2007-02-27

    The two-dimensional self-assembly at the air/water (A/W) interface of two dendrimer-like copolymers based on polystyrene and poly(tert-butyl acrylate) (PS-b-PtBA) or poly(acrylic acid) (PS-b-PAA) was investigated through surface pressure measurements (isotherms, isochores, and compression-expansion hysteresis experiments) and atomic force microscopy (AFM) imaging. The two dendrimer-like block copolymers have an 8-arm PS core (Mn = 10 000 g/mol, approximately 12 styrene repeat units per arm) with a 16-arm PtBA (Mn = 230 000 g/mol, approximately 112 tert-butyl acrylate repeat units per arm) or PAA (Mn = 129 000 g/mol, approximately 112 acrylic acid repeat units per arm) corona. The PS-b-PtBA sample forms stable Langmuir monolayers and aggregates into circular surface micelles up to a plateau observed in the corresponding isotherm around 24 mN/m. Beyond this threshold, the monolayers collapse above the interface, resulting in the formation of large and irregular desorbed aggregates. The PS-b-PAA sample has ionizable carboxylic acid groups, and its A/W interfacial self-assembly was therefore investigated for various subphase pH values. Under basic conditions (pH = 11), the carboxylic acid groups are deprotonated, and the PS-b-PAA sample is therefore highly water-soluble and does not form stable monolayers, instead irreversibly dissolving in the aqueous subphase. Under acidic conditions (pH = 2.5), the PS-b-PAA sample is less water-soluble and becomes surface-active. The pseudoplateau observed in the isotherm around 5 mN/m corresponds to a pancake-to-brush transition with the PAA chains dissolving in the water subphase and stretching underneath the anchoring PS cores. AFM imaging revealed the presence of circular surface micelles for low surface pressures, whereas the biphasic nature of the pseudoplateau region was confirmed with the gradual aggregation of the micellar PS cores above the PAA chains. The aggregation numbers for both samples were estimated around 3

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

    Science.gov (United States)

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

    2014-07-01

    In this study, a strain (BL 101) of a species of Lasiodiplodia, not yet formally described, which was isolated from declining grapevine plants showing wedge-shaped cankers, was investigated for its ability to produce in vitro bioactive secondary metabolites. From culture filtrates of this strain three jasmonic acid esters, named lasiojasmonates A-C and 16-O-acetylbotryosphaerilactones A and C were isolated together with (1R,2R)-jasmonic acid, its methyl ester, botryosphaerilactone A, (3S,4R,5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone and (3R,4S)-botryodiplodin. The structures of lasiojasmonates A-C were established by spectroscopic methods as (1R*,2R*,3'S*,4'R*,5'R*)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone, (1R*,2R*,3'S*,4'R*,5'R*,10'R*,12'R*,13'R*,14'S*) and (1R*,2R*,3'S*,4'R*,5'R*,10'S*,12'R*,13'R*,14'S*)-4-(4-hydroxymethyl-3,5-dimethyltetrahydro-furan-2-yloxymethyl)-3,5-dimethyldihydro-2-furanones jasmonates (1, 4 and 5). The structures of 16-O-acetylbotryosphaerilactones A and C were determined by comparison of their spectral data with those of the corresponding acetyl derivatives obtained by acetylation of botryosphaerilactone A. The metabolites isolated, except 4 and 5, were tested at 1mg/mL on leaves of grapevine cv. Cannonau and cork oak using the leaf puncture assay. They were also tested on detached grapevine leaves at 0.5mg/mL and tomato cuttings at 0.1mg/mL. In all phytotoxic assays only jasmonic acid was found to be active. All metabolites were inactive in the zootoxic assay at 50 μg/mL. Copyright © 2014. Published by Elsevier Ltd.

  19. Modification of ceftibuten transport by changes in lipid fluidity caused by fatty acid glycerol esters.

    Science.gov (United States)

    Koga, K; Murakami, M; Kawashima, S

    1999-01-01

    The effects of various fatty acid glycerol esters (FAGE) on the transport of ceftibuten in rat intestinal brush-border membrane vesicles (BBMV) were investigated. The HLB numbers of FAGE used were in the range of 6.5 to 15.7. The ceftibuten uptake by BBMV was examined by a rapid filtration method in the presence or absence of FAGE of a non-solubilizing concentration (0.03%, w/v). Tetraglycerol monostearate, hexaglycerol monostearate, hexaglycerol sesquistearate, hexaglycerol tristearate and decaglycerol tristearate were found significantly to enhance the ceftibuten uptake under an inward H+-gradient condition, while FAGE with oleate or laurate did not affect it. The extent of ceftibuten uptake with FAGE correlated with the HLB of the esters (r= -0.90, pceftibuten uptake induced by FAGE proved to correlate with an increase in fluidity of the outer lipid layer (r= -0.83, pceftibuten transport in the presence of the H+-gradient should, at least in part, be explained by the interaction with the outer lipid regions of BBMV.

  20. Separation and purification of the antioxidant compounds, caffeic acid phenethyl ester and caffeic acid from mushrooms by molecularly imprinted polymer.

    Science.gov (United States)

    Li, Ning; Ng, Tzi Bun; Wong, Jack Ho; Qiao, Ji Xuan; Zhang, Ye Ni; Zhou, Rong; Chen, Rong Rong; Liu, Fang

    2013-08-15

    Caffeic acid phenethyl ester (CAPE) and caffeic acid (CA), two naturally occurring phenolic antioxidants, have been reported to have a diversity of biological activities. In this investigation, a novel approach to separate and enrich CAPE and CA from 25 species of mushrooms using molecularly imprinted polymers (MIPs) as the sorbent material is reported. The MIPs were synthesized using CAPE as the template, and its adsorption behavior was investigated in detail. In comparison with C18-solid phase extraction (SPE), MIP-SPE displayed high selectivity and good affinity for CAPE and CA. The antioxidant potential of the mushroom extracts, before and after preconcentration using MIPs, was assayed by inhibition of erythrocyte hemolysis and lipid peroxidation. Application of MIPs with a high affinity toward CAPE and CA provides a novel method for obtaining active compounds from natural products. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-06-01

    Five new saccharide fatty acid esters, named nonioside P (3), nonioside Q (4), nonioside R (8), nonioside S (10), and nonioside T (14), and one new succinic acid ester, butyl 2-hydroxysuccinate (=4-butoxy-3-hydroxy-4-oxobutanoic acid) (31), were isolated, along with 26 known compounds, including eight saccharide fatty acid esters, 1, 2, 5, 6, 7, 9, 12, and 13, three hemiterpene glycosides, 15, 17, and 18, six iridoid glycosides, 21-25, and 27, and nine other compounds, 20, 28, 29, and 32-37, from a MeOH extract of the fruit of Morinda citrifolia (noni). Upon evaluation of these and five other glycosidic compounds, 11, 16, 19, 26, and 30, from M. citrifolia fruit extract for their inhibitory activities against melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), most of the saccharide fatty acid esters, hemiterpene glycosides, and iridoid glycosides showed inhibitory effects with no or almost no toxicity to the cells. These compounds were further evaluated with respect to their cytotoxic activities against two human cancer cell lines (HL-60 and AZ521) and their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  2. Analysis of testosterone fatty acid esters in the digestive gland of mussels by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Guercia, Cesare; Cianciullo, Piergiorgio; Porte, Cinta

    2017-07-01

    Several studies have indicated that up to 70% of the total steroids detected in molluscs are in the esterified form and that pollutants, by modifying the esterification of steroids with fatty acids, might act as endocrine disrupters. However, despite the strong physiological significance of this process, there is almost no information on which fatty acids form the steroid esters and how this process is modulated. This study (a) investigates the formation of fatty acid esters of testosterone in digestive gland microsomal fractions of the mussel Mytilus galloprovincialis incubated with either palmitoly-CoA or CoA and ATP, and (b) assesses whether the endocrine disruptor tributyltin (TBT) interferes with the esterification of testosterone. Analysis of testosterone esters was performed by liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). When microsomal fractions were incubated with testosterone and palmitoly-CoA, the formation of testosterone palmitate was detected. However, when microsomes were incubated with CoA and ATP, and no exogenous activated fatty acid was added, the synthesis of 16:0, 16:1, 20:5 and 22:6 testosterone esters was observed. The presence of 100µM TBT in the incubation mixture did not significantly alter the esterification of testosterone. These results evidence the conjugation of testosterone with the most abundant fatty acids in the digestive gland microsomal fraction of mussels. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Soybean biodiesel methyl esters, free glycerin and acid number quantification by 1H nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Coral, Natasha; Rodrigues, Elizabeth; Rumjanek, Victor; Zamian, José Roberto; da Rocha Filho, Geraldo Narciso; da Costa, Carlos Emmerson Ferreira

    2013-02-01

    Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. (1)H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite-type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Synthesis and luminescent properties of the novel poly(ethylene-co-acrylic acid) films based on surface modification with lanthanide (Eu3+, Tb3+) complexes

    Science.gov (United States)

    Wu, Yuewen; Chu, Yang; Yu, Zhenjiang; Hao, Haixia; Wu, Qingyao; Xie, Hongde

    2017-10-01

    Two kinds of novel fluorescent films have been successfully synthesized by surface modification on the poly(ethylene-co-acrylic acid) films using the lanthanide (Eu3+, Tb3+) complexes. The process consists of three steps: conversion of carboxylic acid groups on the surface of the poly(ethylene-co-acrylic acid) films to acid chloride groups, synthesis of the lanthanide complexes bearing amino groups, and amidation to form the modified films. To characterize the modified films, Fourier transform infrared, thermogravimetric analysis, static water contact angle measurements and photoluminescence tests have been employed. Fourier transform infrared verifies the successful preparation of the lanthanide complexes and the modified poly(ethylene-co-acrylic acid) films. These films can emit strong characteristic red and green light under UV light excitation. In addition, the films both have short lifetime (1.14 ms and 1.21 ms), high thermal stability (Td = 408 °C and 411 °C) and, compared with unmodified ones, increased hydrophilicity. All these results suggest that the modified films have potential application as luminescent materials under high temperature.

  5. Process for the conversion of C-terminal peptide esters or acids to amides employing subtilisin in the presence of ammonium salts

    NARCIS (Netherlands)

    Eggen, I.F.; Boeriu, C.G.

    2008-01-01

    The present invention relates to a process for the amidation of C-terminal esters or acids of peptide substrates in solution-phase synthesis of peptides, comprising amidating one or more peptide substrates comprising C-terminal esters or acids using the protease subtilisin in any suitable form in

  6. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729 Boric...

  7. Solubility Testing of Sucrose Esters of Fatty Acids in International Food Additive Specifications.

    Science.gov (United States)

    Nagai, Yukino; Kawano, Satoko; Motoda, Kenichiro; Tomida, Masaaki; Tatebe, Chiye; Sato, Kyoko; Akiyama, Hiroshi

    2017-03-01

    We investigated the solubility of 10 samples of sucrose esters of fatty acids (SEFA) products that are commercially available worldwide as food additives (emulsifiers). Although one sample dissolved transparently in both water and ethanol, other samples produced white turbidity and/or precipitates and did not meet the solubility criterion established by the Joint Food and Agriculture Organization of the United Nations (FAO)/WHO Expert Committee on Food Additives (JECFA). When the sample solutions were heated, the solubility in both water and ethanol increased. All of the samples dissolved transparently in ethanol, and dispersed and became white without producing precipitates in water. The present study suggests that the current solubility criterion of the JECFA SEFA specifications needs to be revised.

  8. Efficient Synthesis and Anti-Fungal Activity of Oleanolic Acid Oxime Esters

    Directory of Open Access Journals (Sweden)

    Xiaomei Liang

    2013-03-01

    Full Text Available In order to develop potential glucosamine-6-phosphate synthase inhibitors and anti-fungal agents, twenty five oleanolic acid oxime esters were synthesized in an efficient way. The structures of the new compounds were confirmed by MS, HRMS, 1H-NMR and 13C-NMR. Preliminary studies based on means of the Elson-Morgan method indicated that many compounds exhibited some inhibitory activity of glucosamine-6-phosphate synthase (GlmS, and the original fungicidal activities results showed that some of the compounds exhibited good fungicidal activities towards Sclerotinia sclerotiorum (Lib. de Bary, Rhizoctonia solani Kuhn and Botrytis cinerea Pers at the concentration of 50 µg/mL. These compounds would thus merit further study and development as antifungal agents.

  9. Synergetic deoxy reforming of cellulose and fatty acid esters for liquid hydrocarbon-rich oils.

    Science.gov (United States)

    Wang, Chao; Sui, Jingjing; Lu, Weipeng; Li, Baopeng; Li, Guoxing; Ding, Yihong; Huang, Yong; Geng, Jianxin

    2015-11-01

    A series of liquid hydrocarbons (alkylbenzenes, alkanes, and alkenes) were obtained by a synergetic deoxy reforming (SDR) process of cellulose and linoleic acid methyl ester (LAME) at 350°C and 4-6MPa in a closed system without external source of hydrogen. The liquid product was obtained with a yield of 15wt% at a LAME/cellulose ratio of 0.2. In contrast, the direct deoxy reforming of cellulose produces oil that contains plenty of phenols and oxygen-containing compounds. Due to the insufficiency of water employed (30wt%), a radical reaction pathway was proposed. Quantum chemical calculations indicate that the radicals from LAME interfere with the reactions of the intermediate products from cellulose, being responsible for the removal of phenols and the formation of hydrocarbons. The SDR process offers an embryonic insight in an alternative technique for preparation of hydrocarbon fuels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Chemical modification of nanocellulose with canola oil fatty acid methyl ester.

    Science.gov (United States)

    Wei, Liqing; Agarwal, Umesh P; Hirth, Kolby C; Matuana, Laurent M; Sabo, Ronald C; Stark, Nicole M

    2017-08-01

    Cellulose nanocrystals (CNCs), produced from dissolving wood pulp, were chemically functionalized by transesterification with canola oil fatty acid methyl ester (CME). CME performs as both the reaction reagent and solvent. Transesterified CNC (CNCFE) was characterized for their chemical structure, morphology, crystalline structure, thermal stability, and hydrophobicity. Analysis by Fourier transform infrared (FTIR) and FT-Raman spectroscopies showed that the long chain hydrocarbon structure was successfully grafted onto CNC surfaces. After transesterification the crystal size and crystallinity of nanocrystals were not changed as determined by Raman spectroscopy and wide angle X-ray diffraction (XRD). CNCFE showed higher thermal stability and smaller particle size than unmodified CNCs. Water contact angle measurement indicated the CNCFE surface has significantly higher hydrophobicity than unmodified CNCs. The transesterified CNCs could be potentially used as hydrophobic coatings and reinforcing agents to hydrophobic polymer for nanocomposites. Published by Elsevier Ltd.

  11. Antiviral Properties of Caffeic Acid Phenethyl Ester and Its Potential Application

    Directory of Open Access Journals (Sweden)

    Haci Kemal Erdemli

    2015-12-01

    Full Text Available Caffeic acid phenethyl ester (CAPE is found in variety of plants and well known active ingredient of the honeybee propolis. CAPE showed anti-inflammatory, anticarcinogenic, antimitogenic, antiviral and immunomodulatory properties in several studies. The beneficial effects of CAPE on different health issues attracted scientists to make more studies on CAPE. Specifically, the anti-viral effects of CAPE and its molecular mechanisms may reveal the important properties of virus-induced diseases. CAPE and its targets may have important roles to design new therapeutics and understand the molecular mechanisms of virus related diseases. In this mini-review, we summarize the antiviral effects of CAPE under the light of medical and chemical literature. [J Intercult Ethnopharmacol 2015; 4(4.000: 344-347

  12. Caffeic acid phenethyl ester attenuates IgE-induced immediate allergic reaction.

    Science.gov (United States)

    Nader, Manar A

    2013-04-01

    Caffeic acid phenethyl ester (CAPE) is the active component of honey bee propolis extracts. The results of the current study demonstrate that CAPE attenuated immunoglobulin (Ig)E-mediated allergic response in mast cells. Oral administration of CAPE inhibited IgE-mediated passive cutaneous anaphylaxis. CAPE effectively reduced both histamine and serotonin (5-HT)-induced vascular permeability in rats. CAPE also reduced histamine and leukotrienes (LTs) release from isolated rat peritoneal mast cells. Moreover, CAPE suppressed contraction induced by histamine (3 × 10(-8)-3 × 10(-5) M), 5-HT (3 × 10(-9)-10(-6) M) and adenosine (3 × 10(-8)-10(-5) M) in guinea pig tracheal zigzag. These findings provide evidence that CAPE may serve as an effective therapeutic agent for allergic diseases.

  13. Microbial dynamics in anaerobic enrichment cultures degrading di-n-butyl phthalic acid ester

    DEFF Research Database (Denmark)

    Trably, Eric; Batstone, Damien J.; Christensen, Nina

    2008-01-01

    Although anaerobic biodegradation of di-n-butyl phthalic acid ester (DBP) has been studied over the past decade, only little is known about the microorganisms involved in the biological anaerobic degradation pathways. The aim of this work is to characterize the microbial community dynamics...... losses were observed in the sterile controls (20-22%), substantial DBP biodegradation was found in the enrichment cultures (90-99%). In addition, significant population changes were observed. The dominant bacterial species in the DBP-degrading cultures was affiliated to Soehngenia saccharolytica......, a microorganism described previously as an anaerobic benzaldehyde degrader. Within the archaeal community, there was a shift between two different species of the genus Methanosaeta sp., indicating a highly specific impact of DBP or degradation products on archaeal species. RNA-directed probes were designed from...

  14. The Implications of Recent Recommendations for Managing Patients with Psoriasis Treated with Fumaric Acid Esters.

    Science.gov (United States)

    Foley, Catherine C; Molloy, Oonagh E; Lally, Aoife; Kirby, Brian

    2017-01-01

    Fumaric acid esters (FAEs) are a well-established efficacious systemic treatment for psoriasis. Recent recommendations from the European Medicines Agency suggest monitoring of full blood count every 4 weeks for the duration of therapy for psoriasis. The aim of our study was to assess the incidence of lymphopenia in patients taking FAEs and the impact of recent recommendations for our practice. We reviewed 151 patients treated with FAEs for psoriasis between December 2013 and 2015. Lymphopenia <700 × 109/L was detected within the last 12 months in 36/151 (24%) and lymphopenia <500 × 109/L in 10/151 (7%). Of 39 patients no longer on treatment, 7 (18%) stopped because of persistent lymphopenia. The implementation of these recommendations would have significant resource implications and also likely influence the acceptability of FAEs to patients. Cessation of FAEs necessitates the need for alternative therapy, commonly biologic therapy. © 2017 S. Karger AG, Basel.

  15. Systemic treatment with fumaric acid esters in six paediatric patients with psoriasis in a psoriasis centre.

    Science.gov (United States)

    Steinz, Kirsten; Gerdes, Sascha; Domm, Silja; Mrowietz, Ulrich

    2014-01-01

    Psoriasis is one of the most common inflammatory skin disorders. There are only limited data on systemic treatment in children. To assess the safety and clinical efficacy of the treatment of six paediatric patients with fumaric acid esters (FAE, Fumaderm) for psoriasis. Six patients aged 6-17 years were treated with FAE. Patients underwent regular assessment. Treatment efficacy was evaluated using the Psoriasis Area and Severity Index (PASI) and body surface area (BSA). The mean duration of treatment was 17.8 months. PASI and BSA were determined after 12 weeks. All patients showed improvement in their skin condition, two achieving PASI75, one PASI90 and three PASI100 response. Proteinuria was encountered in one patient and two patients suffered from gastrointestinal discomfort. Treatment was discontinued due to remission in two patients. Treatment with FAE in paediatric patients is a valuable alternative option when systemic treatment is needed.

  16. Process for the conversion of sugars to lactic acid and 2-hydroxy-3-butenoic acid or esters thereof comprising a metallo-silicate material and a metal ion

    DEFF Research Database (Denmark)

    2015-01-01

    A process for the preparation of lactic acid and 2-hydroxy- 3-butenoic acid or esters thereof from a sugar in the presence of a metallo-silicate material, a metal ion and a solvent, wherein the metal ion is selected from one or more of the group consisting of potassium ions, sodium ions, lithium...... ions, rubidium ions and caesium ions....

  17. Diffusion coefficient, porosity measurement, dynamic and equilibrium swelling studies of Acrylic acid/Polyvinyl alcohol (AA/PVA hydrogels

    Directory of Open Access Journals (Sweden)

    Nazar Mohammad Ranjha

    2015-06-01

    Full Text Available Objective of the present work was to synthesize hydrogels of acrylic acid/polyvinyl alcohol (AA/PVA by free radical polymerization by using glutaradehyde (GA as crosslinkers. The hydrogels were evaluated for swelling, diffusion coefficient and network parameters like the average molecular weight between crosslink’s, polymer volume fraction in swollen state, number of repeating units between crosslinks and crosslinking density by using Flory-Huggins theory. It was found that the degree of swelling of AA/PVA hydrogels increases greatly within the pH range 5-7. The gel fraction and porosity increased by increasing the concentration of AA or PVA. Increase in degree of crosslinking, decreased the porosity and inverse was observed in gel fraction. Selected samples were loaded with metoprolol tartrate. Drug release was studied in USP hydrochloric acid solution of pH 1.2 and phosphate buffer solutions of pH 5.5 and 7.5. Various kinetics models like zero order, first order, Higuchi and Peppas model were used for in vitro kinetic studies. The results showed that the drug release followed concentration dependent effect (First order kinetics with non-Fickian diffusion. FTIR and SEM used to study the structure, crystallinity, compatibility, thermal stability and morphology of prepared and drug loaded hydrogels respectively.

  18. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2014-09-03

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  19. Vinyl ether/acrylic acid terpolymer hydrogels synthesized by {gamma}-radiation: characterization, thermosensitivity and pH-sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Guemuesderelioglu, Menemse [Hacettepe University, Chemical Engineering Department, Beytepe, Ankara 06532 (Turkey)]. E-mail: menemse@hacettepe.edu.tr; Topal, Ilknur Uysal [Hacettepe University, Chemical Engineering Department, Beytepe, Ankara 06532 (Turkey)

    2005-08-01

    The radiation copolymerization of hydrophilic ethylene glycol vinyl ether (EGVE), hydrophobic butyl vinyl ether (BVE) and/or acidic comonomer acrylic acid (AA) was realized in the presence of crosslinking agent diethylene glycol divinyl ether (DEGDVE). The swelling studies which were carried out at 4 and 37 deg. C in phosphate buffer solution (PBS, pH 7.4) showed that equilibrium swelling ratios of the hydrogels (except EGVE homopolymer hydrogel) decreases with increasing temperature and swelling process obeys non-Fickian diffusion mechanism. The pH-dependent swelling behaviour of the hydrogels was examined in buffered solutions at various pHs. The swelling process is reversible and pH-dependent for the AA-containing hydrogel. While this hydrogel shows a fully hydrated form at pH>6; it extensively dehydrates below pH 6. The gels are stable after the repeated swelling experiments. The molecular structure of the hydrogels was studied by Fourier Transform Infrared Spectroscopy and their thermal behaviour was investigated by Differential Scanning Calorimetry and Thermal Gravimetric Analysis. The surface and cross-section structures of the gels were examined by a Scanning Electron Microscope.

  20. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Science.gov (United States)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong; Khil, Myung-Seob; Lee, Deok-Won; Ahn, Sung-Jun

    2015-01-01

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  1. Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization.

    Science.gov (United States)

    Wang, Yawen; Song, Xiohui; Wang, Hong; Chen, Hongyu

    2015-07-09

    We present a template-free method for "polymerizing" nanoparticles into long chains without side branches. A variety of nanoparticles are encapsulated in polystyrene-block-poly(acrylic acid) (PSPAA) shells and then used as monomers for their self-assembly. Spherical PSPAA micelles upon acid treatment are known to assemble into cylindrical micelles. Exploiting this tendency, the core-shell nanoparticles are induced to aggregate, coalesce, and then transform into long chains. When more than one type of nanoparticles are used, random and block "copolymers" of nanoparticles can be obtained. Detailed procedures are reported for the PSPAA encapsulation of nanoparticles, homo- and co-polymerization of the core-shell nanoparticles, separation and purification of the resulting nanoparticle chains. Transformations of single-line chains into double- and triple-line chains are also presented. The synergy between the polymer shell and the embedded nanoparticles leads to an unusual chain-growth polymerization mode, giving long nanoparticle chains that are distinct from the products of the traditional step-growth aggregation process.

  2. Radiation-induced controlled polymerization of acrylic acid by RAFT and RAFT-MADIX methods in protic solvents

    Science.gov (United States)

    Sütekin, S. Duygu; Güven, Olgun

    2018-01-01

    The kinetic investigation of one-pot synthesis of poly(acrylic acid) (PAA) prepared via gamma radiation induced controlled polymerization was reported. PAA homopolymers were prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization in the presence of trithiocarbonate-based chain transfer agent (CTA) 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) and also by Reversible Addition-Fragmentation/Macromolecular Design by Inter-change of Xanthates (RAFT/MADIX) polymerization in the presence of a xanthate based CTA O-ethyl-S-(1-methoxycarbonyl) ethyl dithiocarbonate (RA1). The polymerizations were performed at room temperature by the virtue of ionizing radiation. Protic solvents were used for the RAFT polymerization of AA considering environmental profits. The linear first-order kinetic plot, close control of molecular weight by the monomer/CTA molar ratio supported that the polymerization proceeds in a living fashion. The linear increase in molecular weight with conversion monitored by Size Exclusion Chromatography (SEC) is another proof of controlling of polymerization. [Monomer]/[RAFT] ratio and conversion was controlled to obtain PAA in the molecular weight range of 6900-35,800 with narrow molecular weight distributions. Reaction kinetics and effect of the amount of RAFT agent were investigated in detail. Between two different types of CTA, trithiocarbonate based DDMAT was found to be more efficient in terms of low dispersity (Đ) and linear first-order kinetic behavior for the radiation induced controlled synthesis of PAA homopolymers.

  3. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Khil, Myung-Seob [Chonbuk National University, Jeonju (Korea, Republic of); Lee, Deok-Won [Maxillofacial Surgery Dental Hospital, Seoul (Korea, Republic of); Ahn, Sung-Jun [JADAM Co., LTD., Seogwipo (Korea, Republic of)

    2015-01-15

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  4. Optimal Design for Reactivity Ratio Estimation: A Comparison of Techniques for AMPS/Acrylamide and AMPS/Acrylic Acid Copolymerizations

    Directory of Open Access Journals (Sweden)

    Alison J. Scott

    2015-11-01

    Full Text Available Water-soluble polymers of acrylamide (AAm and acrylic acid (AAc have significant potential in enhanced oil recovery, as well as in other specialty applications. To improve the shear strength of the polymer, a third comonomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS, can be added to the pre-polymerization mixture. Copolymerization kinetics of AAm/AAc are well studied, but little is known about the other comonomer pairs (AMPS/AAm and AMPS/AAc. Hence, reactivity ratios for AMPS/AAm and AMPS/AAc copolymerization must be established first. A key aspect in the estimation of reliable reactivity ratios is design of experiments, which minimizes the number of experiments and provides increased information content (resulting in more precise parameter estimates. However, design of experiments is hardly ever used during copolymerization parameter estimation schemes. In the current work, copolymerization experiments for both AMPS/AAm and AMPS/AAc are designed using two optimal techniques (Tidwell-Mortimer and the error-in-variables-model (EVM. From these optimally designed experiments, accurate reactivity ratio estimates are determined for AMPS/AAm (rAMPS = 0.18, rAAm = 0.85 and AMPS/AAc (rAMPS = 0.19, rAAc = 0.86.

  5. Effect of caffeic acid phenethyl ester on bone formation in the expanded inter-premaxillary suture

    Directory of Open Access Journals (Sweden)

    Kazancioglu HO

    2015-12-01

    Full Text Available Hakki Oguz Kazancioglu,1 Sertac Aksakalli,2 Seref Ezirganli,1 Muhammet Birlik,2 Mukaddes Esrefoglu,3 Ahmet Hüseyin Acar1 1Department of Oral and Maxillofacial Surgery, 2Department of Orthodontics, Faculty of Dentistry, 3Department of Histology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey Background: Narrow maxilla is a common problem in orthodontics and dentofacial orthopedics. To solve this problem, a procedure called rapid maxillary expansion (RME has been used. However, relapse tendency is a major problem of RME. Although relapse tendency is not clearly understood, various treatment procedures and new application has been investigated. The present study aimed to investigate the possible effectiveness of caffeic acid phenethyl ester (CAPE on new bone formation in rat midpalatal suture after RME.Materials and methods: Twenty male Sprague Dawley rats were used in this study. The animals were randomly divided into two groups as control and CAPE group. In CAPE group, CAPE was administered systemically via intraperitoneal injection. RME procedure was performed on all animals. For this purpose, the springs were placed on the maxillary incisors of rats and activated for 5 days. After then, the springs were removed and replaced with short lengths of rectangular retaining wire for consolidation period of 15 days. At the end of the study, histomorphometric analysis was carried out to assess of new bone formation.Results: New bone formation was significantly greater in CAPE group than the control group (P<0.05. CAPE enhances new bone formation in midpalatal suture after RME.Conclusion: These results show that CAPE may decrease the time needed for retention. Keywords: rapid maxillary expansion, bone formation, caffeic acid phenethyl ester, midpalatal suture, histopathology

  6. Fatty acid methyl esters are detectable in the plasma and their presence correlates with liver dysfunction.

    Science.gov (United States)

    Aleryani, Samir Lutf; Cluette-Brown, Joanne E; Khan, Zia A; Hasaba, Hasan; Lopez de Heredia, Luis; Laposata, Michael

    2005-09-01

    Methanol is a component of certain alcoholic beverages and is also an endogenously formed product. On this basis, we have proposed that methanol may promote synthesis of fatty acid methyl esters (FAMEs) in the same way that ethanol promotes fatty acid ethyl ester (FAEE) synthesis. We tested the hypothesis that FAMEs appear in the blood after ethanol intake. Patient plasma samples obtained from our laboratory (n=78) were grouped according to blood ethanol concentrations (intoxicated, blood ethanol >800 mg/l) and non-intoxicated. These samples were further subdivided into groups based on whether the patient had normal or abnormal liver function tests (abnormal, defined as > or =1 abnormality of plasma alanine and aspartate aminotransferase, albumin, total bilirubin, and alkaline phosphatase). A separate set of plasma samples were also divided into normal and abnormal groups based on pancreatic function tests (amylase and lipase). There were no patients with detectable ethanol in this group. Patients with abnormalities in pancreatic function tests were included upon recognition of endogenously produced FAMEs by patients with liver function test abnormalities. FAMEs were extracted from plasma and individual species of FAMEs quantified by gas chromatography-mass spectrometry (GC/MS). Increased concentrations of FAME were found in patient samples with evidence of liver dysfunction, regardless of whether or not they were intoxicated (n=21, p=0.01). No significant differences in plasma FAME concentrations were found between patients with normal (n=15) versus abnormal pancreatic function tests (n=22, p=0.72). The presence of FAMEs in human plasma may be related to the existence of liver disease, and not to blood ethanol concentrations or pancreatic dysfunction. The metabolic pathways associated with FAME production in patients with impaired liver function remain to be identified.

  7. Drug survival of fumaric acid esters for psoriasis: a retrospective study.

    Science.gov (United States)

    Ismail, N; Collins, P; Rogers, S; Kirby, B; Lally, A

    2014-08-01

    Fumaric acid esters (FAEs) have been used for over 30 years in the management of psoriasis. To determine drug survival of FAEs in patients with psoriasis, treatment-limiting adverse drug events and the range of effective drug doses. A retrospective, single-centre study assessing all patients commenced on FAEs between October 2003 and July 2012. Demographic data, length of treatment, reasons for discontinuation of FAEs, side-effects and range of doses were recorded. Two hundred and forty-nine patients [160 (64%) male] were included. The mean age at which FAEs were commenced was 44·5 years (range 17-82 years). The mean length of treatment was 28 months (range 1 week to 106 months). In patients who were commenced on FAEs ≥ 4 years before inclusion in this study, the 4-year drug survival was 60% (64/107). FAEs were discontinued in 146/249 patients (59%); this was due to lack of efficacy in 59/146 (40%) and gastrointestinal upset in 39/146 (27%). A very low dose of FAEs (psoriasis in 26 (10%) patients. The mean treatment duration of these patients was 64 months (range 32-106 months). Fumaric acid esters have a 4-year drug survival rate of 60%, which compares favourably with reported 4-year survival rates of 40% for etanercept and adalimumab and 70% for infliximab. Longer drug survival is more likely in the significant subgroup of patients in whom a very low dose of FAEs is sufficient to control disease. The reasons for this are unclear. © 2014 British Association of Dermatologists.

  8. Renal dysfunction in patients taking fumaric acid esters - a retrospective cross-sectional study.

    Science.gov (United States)

    Menzies, S; Ismail, N; Abdalla, A; Collins, P; Kirby, B; Holian, J; Lally, A

    2017-04-01

    Fumaric acid esters (FAE) have been used for over 30 years in the management of psoriasis. There have been a number of case reports linking the use of FAE with nephrotoxicity, including acute renal injury and Fanconi syndrome. However, one large multicentre retrospective trial showed no evidence of renal dysfunction with FAE. The aim of this study was to determine the number of patients in our institution being treated with FAE who developed significant proteinuria or renal dysfunction. This was a single-centre retrospective study assessing all patients on FAE who attended for follow-up during an 18-week period between February and June 2015. Demographics, comorbidities, duration and dose of treatment with FAE, proteinuria, renal function and other biochemical serum abnormalities were recorded. One hundred and twenty-seven patients were included in the study. Eighty-two patients had proteinuria detected at some stage during treatment with FAE, and 18 of these had persistent proteinuria (positive in at least three consecutive specimens, 12 weeks apart). Six patients (five female) developed proximal tubular dysfunction (PTD). The risk factors for the development of PTD appear to be lower bodyweight (P = 0.03), higher dose per weight (P = 0.03) and longer duration of treatment (P = 0.03). Renal dysfunction improved on discontinuation or dose reduction in FAE. Fumaric acid esters are frequently associated with transient or persistent proteinuria. Significant renal dysfunction is rare and usually reversible on dose reduction or discontinuation of FAE. This study highlights the importance of screening for proteinuria. Higher doses per weight of treatment and longer duration of FAE therapy are likely risk factors for PTD. © 2016 European Academy of Dermatology and Venereology.

  9. Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

    Science.gov (United States)

    Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

    2012-01-01

    3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

  10. Improving the sustainability of fatty acid methyl esters (Fame – biodiesel) – assessment of options for industry and agriculture

    NARCIS (Netherlands)

    Jungmeier, G.; Pucker, J.; Ernst, M.; Haselbacher, P.; Lesschen, J.P.; Kraft, A.; Schulzke, T.; Loo, van E.N.

    2016-01-01

    The life cycle based greenhouse gas (GHG) balances of Fatty Acid Methyl Esters (FAME also called “Biodiesel”) from various resources have been set in the Renewable Energy Directive (RED). Due to technology and scientific progress there are various options to improve the GHG balances of FAME. In

  11. Photo-Crosslinked Biodegradable Hydrogels Prepared From Fumaric Acid Monoethyl Ester-Functionalized Oligomers for Protein Delivery

    NARCIS (Netherlands)

    Jansen, Janine; Mihov, George; Feijen, Jan; Grijpma, Dirk W.

    Photo-crosslinkable, fumaric acid monoethyl ester-functionalized triblock oligomers are synthesized and copolymerized with N-vinyl-2-pyrrolidone to form biodegradable photo-crosslinked hydrogels. Poly(ethylene glycol) is used as the middle hydrophilic segment and the hydrophobic segments are based

  12. Free fatty acids and esters can be immobilized by receptor rich membranes from torpedo marmorata but not phospholipid acyl chains

    NARCIS (Netherlands)

    Rousselet, A.; Devaux, P.F.; Wirtz, K.W.A.

    1979-01-01

    A long chain spin labeled fatty acid and the corresponding ester have been introduced into receptor rich membranes from Torpedo Marmorata. Superimposed to a mobile component, typical of the lipid phase, a strongly immobilized component is seen on the ESR spectra, both at low temperature (−4°C) and

  13. Environmental exposure to the plasticizer 1,2-cyclohexane dicarboxylic acid, diisononyl ester (DINCH) in US adults (2000—2012)

    Science.gov (United States)

    Silva, Manori J.; Jia, Tao; Samandar, Ella; Preau, James L.; Calafat, Antonia M.

    2015-01-01

    1,2-Cyclohexane dicarboxylic acid, diisononyl ester (DINCH) is a complex mixture of nine carbon branched-chain isomers. It has been used in Europe since 2002 as a plasticizer to replace phthalates such as di(2-ethylhexyl)phthalate (DEHP) and diisononyl phthalate (DINP). Urinary concentrations of the oxidative metabolites of DINCH, namely cyclohexane-1,2-dicarboxylic acid-monocarboxy isooctyl ester (MCOCH); cyclohexane-1,2-dicarboxylic acid-mono(oxo-isononyl) ester (MONCH); and cyclohexane-1,2-dicarboxylic acid-mono(hydroxy-isononyl) ester (MHNCH), can potentially be used as DINCH exposure biomarkers. The concentrations of MCOCH, MONCH and MHNCH were measured by online solid phase extraction-high performance liquid chromatography-tandem mass spectrometry in urine collected in 2000 (n=114), 2001 (n=57), 2007 (n=23), 2009 (n=118), 2011 (n=94) and 2012 (n=121) from convenience groups of anonymous U.S. adult volunteers with no known DINCH exposure. None of the DINCH metabolites were detected in samples collected in 2000 and 2001. Only one sample collected in 2007 had measureable concentrations of DINCH metabolites. The detection rate for all three metabolites increased from 2007 to 2012. The presence of oxidative metabolites of DINCH in urine suggests that these oxidative metabolites can be used as DINCH biomarkers for exposure assessment even at environmental exposure levels. PMID:23777640

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

    Directory of Open Access Journals (Sweden)

    Prasad E FUNDE

    2008-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Van Wychen, Stefanie; Ramirez, Kelsey; Laurens, Lieve M. L.

    2016-01-13

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

  16. The effects of egg and diacetyl tartaric acid esters of monoglycerides addition on gluten-free sorghum bread quality

    Science.gov (United States)

    The impact of whole egg addition (as is) at 20, 25, or 30% (flour basis) on sorghum bread quality was evaluated. The use of the antistaling agent diacetyl tartaric acid esters of monoglycerides (DATEM) at 0.5% (flour basis) at each of the egg addition levels was also studied. Evaluated quality facto...

  17. Peak alignment and robust principal component analysis of gas chromatograms of fatty acid methyl esters and volatiles

    DEFF Research Database (Denmark)

    Frosch, Stina; Jørgensen, Bo

    2007-01-01

    Gas chromatograms of fatty acid methyl esters and of volatile lipid oxidation products from fish lipid extracts are analyzed by multivariate data analysis [principal component analysis (PCA)]. Peak alignment is necessary in order to include all sampled points of the chromatograms in the data set....

  18. Early detection of renal damage caused by fumaric acid ester therapy by determination of urinary β2-microglobulin.

    Science.gov (United States)

    Häring, N; Mähr, H Sprenger; Mündle, M; Strohal, R; Lhotta, K

    2011-03-01

    Fumaric acid esters are considered efficacious and safe drugs for the treatment of psoriasis. Renal damage, caused either by acute renal injury or Fanconi syndrome, is a recognized side-effect of this therapy. To investigate whether the measurement of urinary excretion of β2-microglobulin, a marker of renal proximal tubular dysfunction, allows early detection of kidney damage before an increase in serum creatinine or significant proteinuria occurs. Urinary β2-microglobulin excretion was measured regularly in 23 patients undergoing fumaric acid ester therapy. Urinary β2-microglobulin remained normal in all 10 male patients. Three (23%) out of 13 female patients experienced an increase in urinary β2-microglobulin excretion. In two of these patients a sharp increase was observed in association with high doses. One further patient had moderately elevated levels on rather low doses of fumaric acid esters. After discontinuing treatment, urinary β2-microglobulin levels returned to normal within a few weeks. Determination of urinary β2-microglobulin possibly allows early detection of renal damage by fumaric acid esters. Female patients seem to be prone to this side-effect, especially when taking high doses. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

  19. Effectiveness and safety of fumaric acid esters in children with psoriasis: a retrospective analysis of 14 patients from The Netherlands

    NARCIS (Netherlands)

    Balak, D.M.; Oostveen, A.M.; Bousema, M.T.; Venema, A.W.; Arnold, W.P.; Seyger, M.M.B.; Thio, H.B.

    2013-01-01

    BACKGROUND: Fumaric acid esters (FAE) are used as an effective and safe oral treatment for plaque psoriasis in adult patients, but little is known about their efficacy and safety in children with psoriasis. OBJECTIVES: To assess the effectiveness and safety of FAE in the treatment of paediatric

  20. gamma-Aminobutyric acid esters. 3. Synthesis, brain uptake, and pharmacological properties of C-18 glyceryl lipid esters of GABA with varying degree of unsaturation.

    Science.gov (United States)

    Jacob, J N; Hesse, G W; Shashoua, V E

    1987-09-01

    A series of 14C-labeled and unlabeled di-gamma-aminobutyric acid esters of glyceryl lipids having zero to three double bonds (stearoyl, oleoyl, linoleoyl, and linolenoyl) were synthesized. Measurements of the octanol/water partition coefficients of the compounds showed an increase with decreasing number of double bonds (i.e., from linolenoyl to stearoyl). The brain-uptake index went up from 31.5 (linolenoyl) to 45.1 (stearoyl) and similarly the brain-penetration index went up from 15 (linolenoyl) to 28 (stearoyl). Intraperitoneal injections of these di-GABA lipid esters produced a substantial inhibition of the general motor activity in mice at a dose of 30 mg/kg; the most active molecules were those containing two and three double bonds, i.e., the linolenoyl and linolenoyl derivatives. This is in reverse order to that predicted by brain-uptake and lipid-solubility properties, suggesting that the structure of the fatty acid side chain may be an additional factor in influencing biological activity.

  1. On the formation of 4-[N,N-bis(2-chloroethyl)amino]phenyl acetic acid esters of hecogenin and aza-homo-hecogenin and their antileukemic activity.

    Science.gov (United States)

    Camoutsis, Charalambos; Trafalis, Dimitrios; Pairas, George; Papageorgiou, Athanasios

    2005-10-01

    The p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid esters of hecogenin and aza-homo-hecogenin have been prepared and their antineoplastic activity was evaluated against two basic drug screening systems in rodents, P388 lymphocytic and L1210 lymphoid murine leukemias. Among the compounds tested, the p-[N,N-bis(2-chloroethyl)amino]phenylacetic acid ester of aza-homo-hecogenin was appeared to possess a significant higher antileukemic effect. These results support that the alkylating esters of hecogenin produce important antitumor activity as well as, indicate that the aza-homo-hecogenin ester exhibits significantly higher activity due to lactam group (-NHCO-) modification.

  2. Amphoteric surfactants containing ?-hydroxy ester group and an amino acid residue

    Directory of Open Access Journals (Sweden)

    Eissa, A. M. F.

    2006-09-01

    Full Text Available A series of amphoteric surfactants containing α-hydroxy ester group and an amino acid residue were prepared with the addition of epoxy derivatives (which were prepared from epoxidation of alkyl methacrylate to different types of amino acids (glycine, alanine, valine, isoleucine, phenylalanine, tyrosine, serine, threonine, aspartic and anthranilic acid.The structures of the prepared compounds were confirmed by infrared spectra, proton magnetic resonance spectra, Mass spectra and elementary analysis. Surface tension, Kraft point, foaming power, critical micelle concentration emulsion and Ca++ stabilities were determined. Antimicrobial activity and biodegradability were also screened.Se prepararon una serie de tensioactivos anfóteros conteniendo un grupo alfa hidroxi éster y un residuo de aminoácido por adición de derivados epoxy (obtenidos mediante epoxidación de metacrilato de alquilo a diferentes tipos de aminoácidos (glicina, alanina, valina, isoleucina, fenilalanina, tirosina, serina, treonina y ácidos aspártico y antranílico. Las estructuras de los compuestos preparados se confirmaron por los espectros de infrarrojo, de masa, resonancia magnética nuclear de protones y análisis elemental. Se determinaron la tensión superficial, el punto de Kraft, el poder espumante, la concentración micelar crítica en emulsión y las estabilidades de Ca++. También se estudiaron la actividad antimicrobiana y la biodegradabilidad.

  3. ω-3 Fatty Acid Ethyl Esters Diminish Postprandial Lipemia in Familial Hypercholesterolemia.

    Science.gov (United States)

    Chan, Dick C; Pang, Jing; Barrett, P Hugh R; Sullivan, David R; Burnett, John R; van Bockxmeer, Frank M; Watts, Gerald F

    2016-10-01

    Impaired postprandial chylomicron metabolism induces hypertriglyceridemia and may increase the risk of atherosclerotic cardiovascular disease. Omega-3 fatty acid ethyl ester (ω-3 FAEE) supplementation decreases plasma triglycerides. However, its effect on postprandial chylomicron metabolism in familial hypercholesterolemia (FH) has not yet been investigated. We aimed to examine the effect of ω-3 FAEE supplementation on postprandial responses in plasma triglycerides, very-low-density lipoprotein (VLDL) apolipoprotein B (apoB)-100, and apoB-48 in FH patients receiving standard cholesterol-lowering treatment. We carried out an 8-week open-label, randomized, crossover intervention trial to test the effect of oral supplementation with 4 g/d ω-3 FAEE (46% eicosapentaenoic acid and 38% docosahexaenoic acid) on postprandial triglyceride, VLDL-apoB-100, and apoB-48 responses in FH patients after ingestion of an oral fat load. Plasma total and incremental triglyceride, VLDL-apoB-100, and apoB-48 0- to 10-hour area under the curve (AUC). ω-3 FAEE supplementation significantly (P lipemia in FH patients receiving standard care; this may have implications for further reducing atherosclerotic cardiovascular disease in this high-risk patient group.

  4. Parallel Synthesis of a Library of Symmetrically- and Dissymmetrically-disubstituted Imidazole-4,5-dicarboxamides Bearing Amino Acid Esters

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2009-01-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters to afford symmetrically- and dissymmetrically-disubstituted imidazole-4,5-dicarboxamides with intramolecularly hydrogen bonded conformations that predispose the presentation of amino acid pharmacophores. In this work, a total of 45 imidazole-4,5-dicarboxamides bearing amino acid esters were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by 1H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR for screening in the Molecular Library Screening Center Network (MLSCN as part of the NIH Roadmap.

  5. Quantification of methyl esters of fatty acids in the oil of Physalis minima by GC-MS

    Directory of Open Access Journals (Sweden)

    Muhammad Nasimullah Qureshi

    2015-02-01

    Full Text Available Objective: To investigate quantification of methyl esters of fatty acids in the oil extracted from Physalis minima (P. minima using gas chromatography-mass spectrometer. Methods: Oil was extracted from the shade dried plant with n-hexane through Soxhlet extraction. Fatty acids that present in the oil were derivatized to fatty acid methyl esters and analysed through gas chromatography-mass spectrometer. Results: A total of nine fatty acids were detected in quantifiable amount in the oil. Both the saturated fatty acids and unsaturated fatty acids were identified. Palmitic acid was found in the highest concentration as 46.83%. Linoleic acid (ω-6 and linolenic acid (ω-3 were obtained in appreciable amount as 16.98% and 14.80% respectively among the unsaturated fatty acids in the oil under study. From the literature review, it appeared that fatty acids were determined for the first time in the oil of P. minima. Conclusions: Presence of these important fatty acids in high amount makes P. minima oil beneficial for health, which can be used in the preparation of phytopharmaceutical or pharmaceutical preparations. Moreover, the results of this study are useful for the phytopharmaceutical industries to establish their quality control profile.

  6. Microwave-assisted cyclizations promoted by polyphosphoric acid esters: a general method for 1-aryl-2-iminoazacycloalkanes

    Directory of Open Access Journals (Sweden)

    Jimena E. Díaz

    2016-09-01

    Full Text Available The first general procedure for the synthesis of 5 to 7-membered 1-aryl-2-iminoazacycloalkanes is presented, by microwave-assisted ring closure of ω-arylaminonitriles promoted by polyphosphoric acid (PPA esters. 1-Aryl-2-iminopyrrolidines were easily prepared from the acyclic precursors employing a chloroformic solution of ethyl polyphosphate (PPE. The use of trimethylsilyl polyphosphate (PPSE in solvent-free conditions allowed for the synthesis of 1-aryl-2-iminopiperidines and hitherto unreported 1-aryl-2-iminoazepanes. The cyclization reaction involves good to high yields and short reaction times, and represents a novel application of PPA esters in heterocyclic synthesis.

  7. Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid Reinforced with Cellulose Nanocrystals

    Directory of Open Access Journals (Sweden)

    Lim Sze Lim

    2017-11-01

    Full Text Available pH-sensitive poly(acrylic acid (PAA hydrogel reinforced with cellulose nanocrystals (CNC was prepared. Acrylic acid (AA was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system.

  8. Organocatalytic synthesis of N-Phenylisoxazolidin-5-ones and a one-pot synthesis of beta-amino acid esters.

    Science.gov (United States)

    Seayad, Jayasree; Patra, Pranab Kumar; Zhang, Yugen; Ying, Jackie Y

    2008-03-06

    A novel N-heterocyclic carbene (NHC)-catalyzed C-N bond formation by the reaction of alpha,beta-unsaturated aldehydes and nitrosobenzene to N-phenylisoxazolidin-5-ones, followed by an acid-catalyzed esterification and Bamberger-like rearrangement in a mild one-pot protocol leads to N-p-methoxyphenyl (N-PMP) protected beta-amino acid esters.

  9. Surface Structure of Acrylate Polymer Adhesives.

    Science.gov (United States)

    Roy, Sandra; Freiberg, Stephan; Leblanc, Claude; Hore, Dennis K

    2017-02-28

    Total internal reflection infrared (IR) absorption and visible-IR sum-frequency spectroscopies were used to study the role of acrylic acid in the evolution of surface structure in a poly(butyl acrylate)-based pressure-sensitive adhesive during the drying process. By monitoring these spectral responses and calculating the heterospectral correlation coefficients, we established that acrylic acid alters the nature of the molecular interactions at the surface. In the absence of acrylic acid, butyl acrylate orientation is driven by the packing of the polymer as the water evaporates. When acrylic acid is present, a rapid ordering of the copolymer takes place as a result of favorable hydrogen-bonding interactions with the surface.

  10. Nicotinic Acid Accelerates HDL Cholesteryl Ester Turnover in Obese Insulin-Resistant Dogs.

    Directory of Open Access Journals (Sweden)

    Jérôme Le Bloc'h

    Full Text Available Nicotinic acid (NA treatment decreases plasma triglycerides and increases HDL cholesterol, but the mechanisms involved in these change are not fully understood. A reduction in cholesteryl ester transfer protein (CETP activity has been advanced to explain most lipid-modulating effects of NA. However, due to the central role of CETP in reverse cholesterol transport in humans, other effects of NA may have been hidden. As dogs have no CETP activity, we conducted this study to examine the specific effects of extended-release niacin (NA on lipids and high-density lipoprotein (HDL cholesteryl ester (CE turnover in obese Insulin-Resistant dogs with increase plasma triglycerides.HDL kinetics were assessed in fasting dogs before and four weeks after NA treatment through endogenous labeling of cholesterol and apolipoprotein AI by simultaneous infusion of [1,2 13C2] acetate and [5,5,5 2H3] leucine for 8 h. Kinetic data were analyzed by compartmental modeling. In vitro cell cholesterol efflux of serum from NA-treated dogs was also measured.NA reduced plasma total cholesterol, low-density lipoprotein cholesterol, HDL cholesterol, triglycerides (TG, and very-low-density lipoprotein TG concentrations (p < 0.05. The kinetic study also showed a higher cholesterol esterification rate (p < 0.05. HDL-CE turnover was accelerated (p < 0.05 via HDL removal through endocytosis and selective CE uptake (p < 0.05. We measured an elevated in vitro cell cholesterol efflux (p < 0.05 with NA treatment in accordance with a higher cholesterol esterification.NA decreased HDL cholesterol but promoted cholesterol efflux and esterification, leading to improved reverse cholesterol transport. These results highlight the CETP-independent effects of NA in changes of plasma lipid profile.

  11. Omega-3 polyunsaturated fatty acids and cardiovascular disease: an emphasis on omega-3-acid ethyl esters 90 for the treatment of hypertriglyceridemia.

    Science.gov (United States)

    Tatsuno, Ichiro

    2014-11-01

    A number of epidemiological/observational studies, as well as large-scale randomized intervention studies, have been conducted to provide evidence for the efficacy of ω-3 fatty acids against atherosclerotic diseases. Currently, ω-3 fatty acids are commercially available in many parts of the world containing the same active ingredients as Lotriga(®) (ω-3-acid ethyl esters 90 [O3AE highly concentrated ω-3 fatty acid ethyl esters, consisting of eicosapentaenoic acid-ethyl ester and docosahexaenoic acid-ethyl ester [EPA-E/DHA-E]). A recent head-to-head comparative study of O3AEE90 versus EPA-E demonstrated that O3AEE90 4g/day led to a significantly greater reduction in triglycerides (TG) than EPA-E 1.8g/day and that O3AEE90 2g/day produced comparable effects on TG to those with EPA-E 1.8g/day. While both agents were shown to be useful in lowering TG, the hallmark feature of O3AEE90, that is, the presence of the DHA-E component versus its absence in EPA-E, needs to be further examined for its clinical implications.

  12. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    Energy Technology Data Exchange (ETDEWEB)

    Bozzi, Annick; Chapiro, Adolphe

    1988-01-01

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60/sup 0/C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and P' a small fragment, and on the other hand trapped PO/sub 2/sup(center dot) radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

  13. Plasma-induced grafting of acrylic acid on bentonite for the removal of U(VI) from aqueous solution

    Science.gov (United States)

    Hongshan, ZHU; Shengxia, DUAN; Lei, CHEN; Ahmed, ALSAEDI; Tasawar, HAYAT; Jiaxing, LI

    2017-11-01

    Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environment-friendly preparation processes is required for the environment-related applications. In this study, acrylic acid (AA) was grafted onto bentonite (BT) to generate an AA-graft-BT (AA-g-BT) composite using a plasma-induced grafting technique considered to be an environment-friendly method. The as-prepared composite was characterized by scanning electron microscopy, x-ray powder diffraction, thermal gravity analysis, Fourier transform infrared spectroscopy and Barrett-Emmett-Teller analysis, demonstrating the successful grafting of AA onto BT. In addition, the removal of uranium(VI) (U(VI)) from contaminated aqueous solutions was examined using the as-prepared composite. The influencing factors, including contact time, pH value, ionic strength, temperature, and initial concentration, for the removal of U(VI) were investigated by batch experiments. The experimental process fitted best with the pseudo-second-order kinetic and the Langmuir models. Moreover, thermodynamic investigation revealed a spontaneous and endothermic process. Compared with previous adsorbents, AA-g-BT has potential practical applications in treating U(VI)-contaminated solutions.

  14. Ultrasensitive Biosensor for the Detection of Vibrio cholerae DNA with Polystyrene-co-acrylic Acid Composite Nanospheres

    Science.gov (United States)

    Rahman, Mahbubur; Heng, Lee Yook; Futra, Dedi; Ling, Tan Ling

    2017-08-01

    An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae ( V. cholerae) DNA was developed based on polystyrene-co-acrylic acid (PSA) latex nanospheres-gold nanoparticles composite (PSA-AuNPs) DNA carrier matrix. Differential pulse voltammetry (DPV) using an electroactive anthraquninone oligonucleotide label was used for measuring the biosensor response. Loading of gold nanoparticles (AuNPs) on the DNA-latex particle electrode has significantly amplified the faradaic current of DNA hybridisation. Together with the use of a reported probe, the biosensor has demonstrated high sensitivity. The DNA biosensor yielded a reproducible and wide linear response range to target DNA from 1.0 × 10-21 to 1.0 × 10-8 M (relative standard deviation, RSD = 4.5%, n = 5) with a limit of detection (LOD) of 1.0 × 10-21 M ( R 2 = 0.99). The biosensor obtained satisfactory recovery values between 91 and 109% ( n = 3) for the detection of V. cholerae DNA in spiked samples and could be reused for six consecutive DNA assays with a repeatability RSD value of 5% ( n = 5). The electrochemical biosensor response was stable and maintainable at 95% of its original response up to 58 days of storage period.

  15. A drug-loaded gel based on polyelectrolyte complexes of poly (acrylic acid) with poly (vinylpyrrolidone) and chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Jin Shuping [Key Laboratory of Resources and Environmental Chemistry of West China, Department of Chemistry, Hexi University, Zhangye 734000 (China); Liu Mingzhu, E-mail: mzliu@lzu.edu.cn [Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen Shilan [Department of Chemistry, Chongqing University of Science and Technology, Chongqing 401331 (China); Gao Chunmei [Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2010-10-01

    A drug-loaded gel (CSPP) based on ionic crosslinked chitosan (CS) and polyelectrolyte complexes of poly (acrylic acid) (PAA) with poly (vinylpyrrolidone) (PVP) was prepared by dropping CS solution containing suitable amount of PVP into PAA and trisodium citrate co-existing gelling solution. The surface and cross-section morphology of the gel was observed using scanning electron microscopy, and the observation showed that the CSPP gel had more compact structure than CS gel. In vitro release profiles of model drug from the CSPP gel, which was prepared under different conditions, were investigated in simulative gastric fluid (pH 1.8) using an UV/vis spectrophotometer. The results showed that the rapid release of the model was restrained due to the complex of PVP and PAA, and the CSPP gel could serve as a suitable candidate in drug delivery system such as the site-specific controlled release of the drug in stomach. In addition, the release mechanism of drug was analyzed by fitting the amount of drug released into Peppa's potential equation.

  16. Bacterial cellulose/acrylic acid hydrogel synthesized via electron beam irradiation: accelerated burn wound healing in an animal model.

    Science.gov (United States)

    Mohamad, Najwa; Mohd Amin, Mohd Cairul Iqbal; Pandey, Manisha; Ahmad, Naveed; Rajab, Nor Fadilah

    2014-12-19

    Natural polymer-based hydrogels are of interest to health care professionals as wound dressings owing to their ability to absorb exudates and provide hydration for healing. The aims of this study were to develop and characterize bacterial cellulose/acrylic acid (BC/AA) hydrogels synthesized by electron beam irradiation and investigate its wound healing potential in an animal model. The BC/AA hydrogels were characterized by SEM, tensile strength, water absorptivity, and water vapor transmission rate (WVTR). The cytotoxicity of the hydrogels was investigated in L929 cells. Skin irritation and wound healing properties were evaluated in Sprague-Dawley rats. BC/AA hydrogels had a macroporous network structure, high swelling ratio (4000-6000% at 24h), and high WVTR (2175-2280 g/m(2)/day). The hydrogels were non-toxic in the cell viability assay. In vivo experiments indicated that hydrogels promoted faster wound-healing, enhanced epithelialization, and accelerated fibroblast proliferation compared to that in the control group. These results suggest that BC/AA hydrogels are promising materials for burn dressings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Preparation and swelling behavior of a novel self-assembled β-cyclodextrin/acrylic acid/sodium alginate hydrogel.

    Science.gov (United States)

    Huang, Zhanhua; Liu, Shouxin; Zhang, Bin; Wu, Qinglin

    2014-11-26

    A novel biodegradable β-cyclodextrin/acrylic acid/sodium alginate (CSA) hydrogel with a three-dimensional network structure was self-assembled by inverse suspension copolymerization. The CSA resin was pH sensitive and had good water absorption properties in pH 6-8 buffer solutions. At a β-CD:AA:SA mass ratio of 1:9:3 the CSA water absorbency was found to be 1403 g/g and the CSA hydrogel strength was 4.968 N. In 0.005-0.1 mol/L chloride salt and sulfate salt solutions the CSA water absorbencies increased as follows: NaCl>KCl>MgCl2>CaCl2>FeCl3, and Na2SO4>K2SO4>FeSO4>Al2(SO4)3, respectively. The release of water from the CSA hydrogel occurred slowly over 120 h. The biodegradation efficiency of the resin reached 85.3% for Lentinula edodes. The super water absorbency, good salt resistance and excellent water retention properties of CSA make it suitable for application as an agricultural water retention agent in saline soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Biocompatibility of poly(ethylene glycol) and poly(acrylic acid) interpenetrating network hydrogel by intrastromal implantation in rabbit cornea.

    Science.gov (United States)

    Zheng, Luo Luo; Vanchinathan, Vijay; Dalal, Roopa; Noolandi, Jaan; Waters, Dale J; Hartmann, Laura; Cochran, Jennifer R; Frank, Curtis W; Yu, Charles Q; Ta, Christopher N

    2015-10-01

    We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 months. Rabbits were evaluated monthly. After the assigned period, eyes were enucleated, and corneas were processed for histology and immunohistochemistry. There were clear corneas in three of six rabbits that had implantation of hydrogel for 2 months. In the six rabbits with implant for 6 months or longer, the corneas remained clear in four. There was a high rate of epithelial defect and corneal thinning in these six rabbits. One planned 9-month rabbit developed extrusion of implant at 4 months. The cornea remained clear in the 16-month rabbit but histology revealed epithelial in-growth. Intrastromal implantation of PEG/PAA resulted in a high rate of long-term complications. © 2015 Wiley Periodicals, Inc.

  19. Synthesis of a Nanostructured Molecularly Imprinted Acrylic acid-Based Network Copolymer as a Solid Sorbentforthe Quercetinextraction

    Directory of Open Access Journals (Sweden)

    A. Amiri

    2014-07-01

    Full Text Available A straightforward approach for the extraction of the quercetin was carried out by a nanoporous molecularly imprinted acrylic acid-based network copolymer as asolid sorbent. This technique involves a molecular template (quercetin which is surrounded by functional monomers and are subsequently co-polymerized in the presence of an excess of the cross linkers. In this process, three-dimensional binding sites are generated that are complementary to the quercetin template in terms of size, shape and position of functional groups. After removal of the imprinting quercetin template, the nanostructured polymer can therefore specifically recognize and re-bind the same or structurally very similar molecules. The synthesized MIP by bulk polymerization was exhibited a good tendency to absorb the quercetin template in a solid phase extraction (SPE system. The prepared MIP achieved a binding capacity of 169 mg/grfor the quercetin in acetonitrile-water (1:1 v/v solvent. Imaging by scanning electron microscope (SEM was carried out to determine the surface morphology of the prepared MIP.

  20. Determination of Monomers Reactivity Ratios in Ethyl Acrylate-Methacrylic Acid Copolymerization by Off-Line 1H NMR

    Directory of Open Access Journals (Sweden)

    Samaneh Ashenagar

    2017-03-01

    Full Text Available The physical, chemical and mechanical properties of polymer systems depend on the micro-structural characteristics of their macromolecular chains. Along with the most characteristic kinetic parameters in copolymerization reactions are the reactivity ratios, which give a clear idea of the average composition and the monomer sequence distribution in copolymer systems. This research studies the solution radical copolymerization of methacrylic acid (MAA-ethyl acrylate (EA system at low conversion with 2,2'-azobisisobutyronitrile (AIBN as thermal initiator at 60°C in deuterated dimethyl sulfoxide (DMSO-d6 as a reaction solvent. In this case, the monomer reactivity ratios were determined using linear off-line 1H nuclear magnetic resonance spectroscopy (1H NMR methods such as Mayo-Louis, Finemann-Ross, Inverted Finemann-Ross , Ezrielev-Brokhina-Roskin, Joshi-Joshi, Kelen-Tudos, extended Kelen- Tudos, Mao-Huglin at low and high conversions. The next estimation process in off-line 1H NMR methods were performed by applying techniques based on ordinary least square (OLS and generalized least square (GLS. The results showed that the GLS approach compared to the OLS increased regression coefficients (R2 and the order of magnitude of parameter variances obtained from GLS was many times lower than that obtained from OLS. In addition, the monomer reactivity ratios obtained by the Mao-Huglin method and the GLS approach showed the best linear estimation.

  1. A quantitative study of the enzymatic activity of horseradish peroxidase at a planar poly(acrylic acid) brush.

    Science.gov (United States)

    Reichhart, Christian; Czeslik, Claus

    2010-02-01

    The enzymatic activity of horseradish peroxidase (HRP) has been quantified at a planar poly(acrylic acid) (PAA) brush. A PAA brush is known to exhibit an unusual protein binding affinity, since proteins adsorb at low ionic strength only. At elevated ionic strengths of a few 100 mM proteins desorb, and the PAA brush becomes largely protein resistant. In this study, HRP was used to catalyze the oxidation of Amplex Red to resorufin by hydrogen peroxide. The fluorescence of resorufin was recorded using a microplate reader. As compared to a bare silica surface, the enzymatic activity of HRP is higher by more than one order of magnitude at a PAA brush. This increase results from a higher degree of adsorption and a reasonable preservation of the HRP activity. Upon adsorption at a PAA brush from a 20 mU/mL (0.1 microg/mL) solution, the molecular enzymatic activity of HRP is reduced to about 11%. However, when a HRP molecule is desorbed from a PAA brush by increasing the ionic strength, a gain of the molecular enzymatic activity by only 52% can be observed. Overall, this study illustrates the potential applicability of a PAA brush as a biocompatible material coating.

  2. Preparation of anion exchanger by amination of acrylic acid grafted polypropylene nonwoven fiber and its ion-exchange property.

    Science.gov (United States)

    Park, Hyun-Ju; Na, Choon-Ki

    2006-09-01

    To develop the polymeric adsorbent that possess anionic exchangeable function, PP-g-AA-Am fibers were prepared by photoinduced grafting of acrylic acid (AA) onto polypropylene (PP) nonwoven fibers and subsequent conversion of carboxyl group in grafted AA to an amine (Am) group by reaction with diethylene triamine (DETA). The amination of grafted AA increased with increase in the degree of grafting, the reaction time and temperature of the chemical modification process. Catalytic effect of metal chlorides such as AlCl(3) and FeCl(3) on the amination of grafted AA was significant but not essential to lead the amination. FT-IR and solid (13)C NMR data indicate that amine group was introduced into PP-g-AA fiber through amide linkage between grafted AA and DETA. The anion exchange capacity of PP-g-AA-Am fiber increased with increase in the degree of amination, but reached maximum value at about 60% amination of 150% grafted AA. PP-g-AA-Am fiber showed much higher maximum capacity for PO(4)-P and a similar capacity for NO(3)-N compared to commercial anion resins. Furthermore, the PP-g-AA-Am fiber also has adsorption ability for cations because of unaminated residual carboxyl group.

  3. Effects Of Environmental Factors On The Dispersion Behavior Of Iron Oxide In Aqueous Solutions With Poly Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Lee E.-H.

    2015-06-01

    Full Text Available After preparing aqueous suspensions from magnetite particles with a poly-acrylic acid, we investigated the effects of several experimental parameters. We characterized the stability of the suspensions using visual inspection, sedimentation, adsorption, and thermal stability of the dispersant. The dispersion stability is affected by the solution pH, the concentrations of magnetite particles, the molecular weight, the concentration of the dispersants, and the temperature. The stability of the suspensions increased as the concentration of the dispersant and the temperature increased. In terms of the molecular weights of the dispersant, the suspensions with dispersant of low-molecular weight (1800 were more stable than those of high-molecular weight (250000 at room temperature. However, at high temperature the suspensions with high-molecular weight showed stability. The adsorption efficiency of the dispersant was very low. The dispersant of high-molecular weight showed a higher thermal integrity than that of low-molecular weight. From this work, we obtained the optimum conditions for stable aqueous suspensions of magnetite particles.

  4. Superabsorbent nanocomposite synthesis of cellulose from rice husk grafted poly(acrylate acid-co-acrylamide)/bentonite

    Science.gov (United States)

    Helmiyati; Abbas, G. H.; Kurniawan, S.

    2017-04-01

    Superabsorbent nanocomposite synthesis of cellulose rice husk as the backbone with free radical polymerization method in copolymerization grafted with acrylic acid and acrylamide monomer. The cellulose was isolated from rice husk with mixture of toluene and ethanol and then hemicellulose and lignin were removed by using potassium hydroxide 4% and hydrogen peroxide 2%. The obtained cellulose rendement was 37.85%. The functional group of lignin analyzed by FTIR spectra was disappeared at wavenumber 1724 cm-1. Crystal size of the obtained isolated cellulose analyzed by XRD diffraction pattern was 34.6 nm, indicated the nanocrystal structure. Copolymerization was performed at temperature of 70°C with flow nitrogen gas. Initiator and crosslinking agent used were potassium persulfate and N‧N-methylene-bis-acrylamide. The swelling capacity of water and urea showed the results was quite satisfactory, the maximum swelling capacity in urea and water were 611.700 g/g and 451.303 g/g, respectively, and can be applied in agriculture to absorb water and urea fertilizer.

  5. Preparation of mesoporous poly (acrylic acid)/SiO2 composite nanofiber membranes having adsorption capacity for indigo carmine dye

    Science.gov (United States)

    Xu, Ran; Jia, Min; Li, Fengting; Wang, Hongtao; Zhang, Bingru; Qiao, Junlian

    2012-03-01

    Mesoporous poly (acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber membranes functionalized with mercapto groups were fabricated by a sol-gel electrospinning method, and their adsorption capacity for indigo carmine was investigated. The membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray powder diffraction (XRD), and nitrogen adsorption-desorption measurement. SEM and TEM observation results showed that the PAA/SiO2 fibers had diameters between 400-800 nm and mesopores with an average pore size of 3.88 nm. The specific surface area of the mesoporous nanofiber membranes was 514.89 m2/g. The characteristic peaks for mercapto group vibration in FTIR and Raman spectra demonstrated that the mercapto groups have been incorporated into the silica skeleton. The adsorption isotherm data of indigo carmine on the membranes fit well with Redlich-Peterson model, and the maximum adsorption capacity calculated was 523.11 mg/g. It was found that the removal rate of indigo carmine by the membranes reached a maximum of 98% in 90 min and the adsorption kinetics followed a pseudo-second-order model. The high adsorption capacity of PAA/SiO2 nanofiber membrane makes it a promising adsorbent for indigo carmine removal from the wastewater.

  6. Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Honglong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Lu; Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Pang, Lijuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Hu, Jiangtao; Wang, Mouhua [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong, E-mail: wuguozhong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-09-30

    Highlights: • Hydrophilic UHMWPE powder and film were obtained by γ-ray pre-irradiation grafting of AA. • A low concentration of AA solution was used for surface modification of UHMWPE. • A small grafting yield of AA sufficiently improved hydrophilicity of UHMWPE powder and film. - Abstract: The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

  7. Graphene oxide/poly(acrylic acid)/gelatin nanocomposite hydrogel: experimental and numerical validation of hyperelastic model.

    Science.gov (United States)

    Faghihi, Shahab; Karimi, Alireza; Jamadi, Mahsa; Imani, Rana; Salarian, Reza

    2014-05-01

    Owing to excellent thermal and mechanical properties, graphene-based nanomaterials have recently attracted intensive attention for a wide range of applications, including biosensors, bioseparation, drug release vehicle, and tissue engineering. In this study, the effects of graphene oxide nanosheet (GONS) content on the linear (tensile strength and strain) and nonlinear (hyperelastic coefficients) mechanical properties of poly(acrylic acid) (PAA)/gelatin (Gel) hydrogels are evaluated. The GONS with different content (0.1, 0.3, and 0.5 wt.%) is added into the prepared PAA/Gel hydrogels and composite hydrogels are subjected to a series of tensile and stress relaxation tests. Hyperelastic strain energy density functions (SEDFs) are calibrated using uniaxial experimental data. The potential ability of different hyperelastic constitutive equations (Neo-Hookean, Yeoh, and Mooney-Rivlin) to define the nonlinear mechanical behavior of hydrogels is verified by finite element (FE) simulations. The results show that the tensile strength (71%) and elongation at break (26%) of composite hydrogels are significantly increased by the addition of GONS (0.3 wt.%). The experimental data is well fitted with those predicted by the FE models. The Yeoh material model accurately defines the nonlinear behavior of hydrogels which can be used for further biomechanical simulations of hydrogels. This finding might have implications not only for the improvement of the mechanical properties of composite hydrogels but also for the fabrication of polymeric substrate materials suitable for tissue engineering applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    Directory of Open Access Journals (Sweden)

    M. Golzar

    2014-01-01

    Full Text Available Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA prevents iron nanoparticles from forming large flocs that may cause sedimentation and so increases transport distance of the nanoparticles. In this study, the transport of iron oxide nanoparticles (Fe3O4 stabilized with PAA in a one-dimensional porous media (column was investigated. The slurries with concentrations of 20,100 and 500 (mg/L were injected into the bottom of the column under hydraulic gradients of 0.125, 0.375, and 0.625. The results obtained from experiments were compared with the results obtained from numerical solution of advection-dispersion equation based on the classical colloid filtration theory (CFT. The experimental and simulated breakthrough curves showed that CFT is able to predict the transport and fate of iron oxide nanoparticles stabilized with PAA (up to concentration 500 ppm in a porous media.

  9. Chitosan-modified poly(acrylonitrile-co-acrylic acid) nanofibrous membranes for the immobilization of concanavalin A.

    Science.gov (United States)

    Che, Ai-Fu; Liu, Zhen-Mei; Huang, Xiao-Jun; Wang, Zhen-Gang; Xu, Zhi-Kang

    2008-12-01

    Lectin affinity membranes have been receiving much attention for the separation and detection of various glycoconjugates. In this work, we present a simple and efficient method for the preparation of lectin affinity nanofibrous membranes. Chitosan-modified poly(acrylonitrile-co-acrylic acid) (PANCAA) nanofibrous membranes were first prepared by a coupling reaction between the primary amino groups of chitosan and the carboxyl groups of PANCAA electrospun membranes. Surface characterizations by attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM) confirm the chemical and morphological changes of the studied nanofibrous membranes. Fluorescence-labeled concanavalin A (FL-Con A) was then immobilized on these membranes via noncovalent binding. Analyses by fluorescence spectrophotometer (FS) and confocal laser scanning microscopy (CLSM) reveal that the immobilization of Con A onto the modified nanofibrous membranes has been successfully achieved on the basis of the electrostatic interaction and the specific recognition between Con A and chitosan. The results show that the amount of adsorbed FL-Con A increases dramatically with the increasing coupling degree of chitosan (CDC) on the nanofibrous membrane. Moreover, Con A immobilized on the chitosan-modified nanofibrous membranes (CMNMs) can remain relatively stable at pH 5.3. Therefore, it is believed that this work may provide a new kind of material for affinity application.

  10. Characterization and Antimicrobial Property of Poly(Acrylic Acid Nanogel Containing Silver Particle Prepared by Electron Beam

    Directory of Open Access Journals (Sweden)

    Jong-Bae Choi

    2013-05-01

    Full Text Available In this study, we developed a one step process to synthesize nanogel containing silver nanoparticles involving electron beam irradiation. Water-soluble silver nitrate powder is dissolved in the distilled water and then poly(acrylic acid (PAAc and hexane are put into this silver nitrate solution. These samples are irradiated by an electron beam to make the PAAc nanogels containing silver nanoparticles (Ag/PAAc nanogels. The nanoparticles were characterized by scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS. In addition, the particle size and zeta-potential were confirmed by a particle size analyzer (PSA. The antibacterial properties of the nanogels were evaluated by paper diffusion test. The Ag/PAAc nanogels had an antibacterial effect against Escherichia coli and Staphylococcus aureus. The nanogels also demonstrated a good healing effect against diabetic ulcer. The size of the Ag/PAAc nanogels decreased with increasing irradiation doses, and the absolute value of the zeta potential increased with increasing irradiation doses. Also, the Ag/PAAc nanogels exhibited good antibacterial activity against both Gram-negative and Gram-positive bacteria. In in vivo wound healing, the Ag/PAAc nanogels have a good healing effect.

  11. Synthesis of bioadhesive poly(acrylic acid) nano- and microparticles using an inverse emulsion polymerization method for the entrapment of hydrophilic drug candidates.

    Science.gov (United States)

    Kriwet, B; Walter, E; Kissel, T

    1998-12-04

    Bioadhesive latices of water-swollen poly(acrylic acid) nano-and microparticles were synthesized using an inverse (W/O) emulsion polymerization method. They are stabilized by a co-emulsifier system consisting of SpanTM 80 and TweenTM 80 dispersed in aliphatic hydrocarbons. The initial polymerization medium contains emulsion droplets and inverse micelles which solubilize a part of the monomer solution. The polymerization is initiated by free radicals, and particle dispersions with a narrow size distribution are obtained. The particle size is dependent on the type of radical initiator used. With water-soluble initiators, for example ammonium persulfate, microparticles were obtained in the size range of 1 to 10 micrometer indicating that these microparticles originate from the emulsion droplets since the droplet sizes of the W/O emulsion show similar distribution. When lipophilic radical initiators, such as azobis-isobutyronitrile, are used, almost exclusively nanoparticles are generated with diameters in the range of 80 to 150 nm, due to the limited solubility of oligomeric poly(acrylic acid) chains in the lipophilic continuous phase. These poly(acrylic acid) micro- and nanoparticles yielded excellent bioadhesive properties in an in-vitro assay and may, therefore, be suitable for the encapsulation of peptides and other hydrophilic drugs.

  12. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 19: Condensation of phthalic and substituted phthalic anhydrides with benzoylacetic ester

    Science.gov (United States)

    Rotberg, Y. T.; Oshkaya, V. P.

    1985-01-01

    Phthalylbenzoylacetic ester and its nitro and halogen derivatives were prepared through condensation of phthalic anhydride, nitrophthalic anhydride, and phthalic halide anhydride with benzoylacetic ester in a solution of acetic anhydride and triethylamine. The condensation of hemipinic acid anhydride proceeds similarly, but under more drastic conditions. Derivatives of indan-1,3-dione are also formed, with a small yield, in the reaction of nitrophthalic anhydrides with benzoylacetic ester in the presence of increased quantities of triethylamine.

  13. Optimization of reaction parameters for enzymatic glyceride synthesis from fish oil: Ethyl esters versus free fatty acids

    DEFF Research Database (Denmark)

    Ravn, Helle Christine; Damstrup, Marianne L.; Meyer, Anne S.

    2012-01-01

    Enzymatic conversion of fish oil free fatty acids (FFA) or fatty acid ethyl esters (FAE) into glycerides via esterification or transesterification was examined. The reactions catalyzed by Lipozyme™ 435, a Candida antarctica lipase, were optimized. Influence on conversion yields of fatty acid chain...... length, saturation degree, temperature, enzyme dosage, molar ratio glycerol:fatty acids, acyl source composition (w/w ratio FFA:FAE), and reaction time was evaluated collectively by multiple linear regression. All reaction variables influenced the conversion into glycerides. Transesterification of FAE...

  14. Regulatory Effects of Caffeic Acid Phenethyl Ester on Neuroinflammation in Microglial Cells

    Directory of Open Access Journals (Sweden)

    Cheng-Fang Tsai

    2015-03-01

    Full Text Available Microglial activation has been widely demonstrated to mediate inflammatory processes that are crucial in several neurodegenerative disorders. Pharmaceuticals that can deliver direct inhibitory effects on microglia are therefore considered as a potential strategy to counter balance neurodegenerative progression. Caffeic acid phenethyl ester (CAPE, a natural phenol in honeybee propolis, is known to possess antioxidant, anti-inflammatory and anti-microbial properties. Accordingly, the current study intended to probe the effects of CAPE on microglia activation by using in vitro and in vivo models. Western blot and Griess reaction assay revealed CAPE significantly inhibited the expressions of inducible nitric oxide synthase (NOS, cyclooxygenase (COX-2 and the production of nitric oxide (NO. Administration of CAPE resulted in increased expressions of hemeoxygenase (HO-1and erythropoietin (EPO in microglia. The phosphorylated adenosine monophosphate-activated protein kinase (AMPK-α was further found to regulate the anti-inflammatory effects of caffeic acid. In vivo results from immunohistochemistry along with rotarod test also revealed the anti-neuroinflammatory effects of CAPE in microglia activation. The current study has evidenced several possible molecular determinants, AMPKα, EPO, and HO-1, in mediating anti-neuroinflammatory responses in microglial cells.

  15. In vitro enzymatic biodegradation of amino acid based poly(ester amide)s biomaterials.

    Science.gov (United States)

    Tsitlanadze, G; Kviria, T; Katsarava, R; Chu, C C

    2004-02-01

    A systematic in vitro biodegradation study of regular poly(ester amide)s (PEAs) composed of naturally occurring hydrophobic alpha-amino acids, fatty diols and dicarboxylic acids was carried out in the presence of hydrolases like trypsin, alpha-chymotrypsin, and lipase. An automatic potentiometric titration method was used to examine the biodegradation property of the PEAs. Spontaneous immobilization (absorption) of the enzymes onto the PEAs films surfaces was observed. The surface immobilized enzyme not only accelerated the erosion of the PEAs but also was able to catalyze the hydrolysis of both low-molecular-weight (ATEE) and high-molecular-weight (protein) external substrates. It was found that the enzyme surface absorption process is reversible by nature. A kinetic method for a quantitative determination of the enzyme desorbed from the film surface was developed. The enzymes could also be impregnated into the PEAs to make them "self-destructive" at a target rate. A comparison of the PEAs' in vitro biodegradation data with polylactide (PDLLA) showed that PEAs exhibited a far more tendency toward enzyme catalyzed biodegradation than PDLLA.

  16. Synthesis of trimethylolpropane esters of oleic acid by Lipoprime 50T.

    Science.gov (United States)

    Kiriliauskaitė, Vita; Bendikienė, Vida; Juodka, Benediktas

    2011-09-01

    The ability of the commercial lipolytic enzyme Lipoprime 50T to catalyze the biotechnologically important synthesis of the biodegradable and environmentally acceptable trimethylolpropane (2-ethyl-2-(hydroxymethyl)-1,3-propanediol) ester of oleic acid was investigated. Simple and accurate thin-layer chromatography and computer analysis methods were used that enable one to follow changes of all reaction mixture components simultaneously. The processes of transesterification and esterification were compared. The effects of the molar ratio of the substrates, reaction temperature, time, and medium on the composition of the reaction mixture were analyzed. Esterification was determined to be more preferable than transesterification in both studied solvents. Under the optimal conditions identified (15% w/w water, temperature 60°C, trimethylolpropane to oleic acid molar ratio 1:3.5, and reaction time 72 h), the highest trimethylolpropane trioleate yield of around 62% and trimethylolpropane mono-, di-, and trioleate overall yield of about 83% were obtained. Although the yields are not high enough for industrial application, the process shows the potential to be optimized for higher yields in the near future as the conversions were obtained at ambient pressure, whereas many other processes described in the literature are conducted under vacuum at a specific pressure.

  17. Characteristics of Oxidative Storage Stability of Canola Fatty Acid Methyl Ester Stabilised with Antioxidants

    Directory of Open Access Journals (Sweden)

    Tirto Prakoso

    2012-11-01

    Full Text Available The storage effects on the oxidation characteristics of fatty acid methyl ester of canola oil (CME were investigated in this study. CME stabilised with two antioxidants, i.e. 2,6-di-tert-bytyl-p-cresol (BHT and 6,6-di-tert-butyl-2, 2’-methylendi-p-cresol (BPH, was stored at 20, 40 and 60°C. The oxidation stability data were measured by the Rancimat test method and it was found that both BHT and BPH addition increased the oxidation resistance of the CME. The results showed that when BPH or BHT was added at a concentration of 100 ppm, the oxidation induction period of the neat CME samples increased from 5.53 h to 6.93 h and 6.14 h, respectively. Comparing both antioxidants, BPH proved to be more effective in increasing the oxidation resistance when both antioxidants were added at the same concentration. Furthermore, the oxidation induction time decreased linearly with the storage time. It was shown that the oxidation occurred rapidly in the first 8 weeks of storage. Later, a kinetic study was undertaken and first-order kinetics were applied to explain the oxidation characteristics of the CME added with antioxidants. This kinetic study focused on exploiting the activation energy values obtained from the Arrhenius equations. Also, the oxidation effects on other quality parameters, including acid value, peroxide value, kinematic viscosity, and water content, were examined.

  18. Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: a case series.

    Science.gov (United States)

    Balak, Deepak M W; Bouwes Bavinck, Jan Nico; de Vries, Aiko P J; Hartman, Jenny; Neumann, Hendrik A Martino; Zietse, Robert; Thio, Hok Bing

    2016-02-01

    Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fanconi syndrome. Descriptive case series with two cases of Fanconi syndrome associated with FAE treatment diagnosed at two Dutch university nephrology departments, three cases reported at the Dutch and German national pharmacovigilance databases and six previously reported cases. All 11 cases involved female patients with psoriasis. The median age at the time of onset was 38 years [interquartile range (IQR) 37-46]. Patients received long-term FAEs treatment with a median treatment duration of 60 months (IQR 28-111). Laboratory tests were typically significant for low serum levels of phosphate and uric acid, while urinalysis showed glycosuria and proteinuria. Eight (73%) patients had developed a hypophosphataemic osteomalacia and three (27%) had pathological bone fractures. All patients discontinued FAEs, while four (36%) patients were treated with supplementation of phosphate and/or vitamin D. Five (45%) patients had persisting symptoms despite FAEs discontinuation. FAEs treatment can cause drug-induced Fanconi syndrome, but the association has been reported infrequently. Female patients with psoriasis treated long term with FAEs seem to be particularly at risk. Physicians treating patients with FAEs should be vigilant and monitor for the potential occurrence of Fanconi syndrome. Measurement of the urinary albumin:total protein ratio is a suggested screening tool for tubular proteinuria in Fanconi syndrome.

  19. Pharmacokinetics of anti-psoriatic fumaric acid esters in psoriasis patients.

    Science.gov (United States)

    Rostami-Yazdi, Martin; Clement, Bernd; Mrowietz, Ulrich

    2010-09-01

    The aim of this study was to evaluate pharmacokinetic parameters of fumaric acid esters (FAE) in psoriasis patients for the first time. For this prupose new HPLC assays were developed. Additionally, physicochemical parameters of FAE were determined, allowing a better interpretation of the in vivo data. In vivo, monomethylfumarate (MMF) and monoethylfumarate (MEF) were detected after t (lag) = 120 min. T (max) and c (max) of MMF were 210 min and 11.2 microM, respectively, 210 min and 5.2 microM for MEF. The half-life of MMF was 38.7 min, and 25.4 min of MEF. The AUC(0-infinity) of MMF was 172 min microg ml(-1) and 63.6 min microg ml(-1) of MEF. Data display median of three subjects. No plasma levels of dimethylfumarate (DMF) or fumaric acid (FA) were detected. The evaluation of physicochemical parameters of FAE showed that only DMF fulfils the criteria of Lipinski's rule of five. The pKa of MMF was determined as 3.63. The data of this study provide evidence that DMF is most likely absorbed out of the duodenum into the presystemic circulation and is not completely hydrolysed to MMF before uptake as assumed by others.

  20. Lupeol long-chain fatty acid esters with antimalarial activity from Holarrhena floribunda.

    Science.gov (United States)

    Fotie, Jean; Bohle, D Scott; Leimanis, Mara L; Georges, Elias; Rukunga, Geoffrey; Nkengfack, Augustin E

    2006-01-01

    An ethnopharmacological investigation was conducted among the Baka pygmies of Dja biosphere reserve (Cameroon) to collect information on the antimalarial plants used in their daily life. Holarrhena floribunda is one of those plants. Extracts of the stem barks of H. floribunda showed remarkable inhibitory activity against drug-resistant strains of Plasmodium falciparum at doses of 1.02-18.53 microg/mL when tested in vitro against two parasite clones designated as Indochina (W-2) and Sierra Leone (D-6). The aqueous extract was the most active against Indochina (W-2), with IC50 values of 1.02 microg/mL, while the ethanolic extract appeared to be the most active against Sierra Leone (D-6), with an IC50 of 4.33 microg/mL. The bioassay-guided fractionation of the neutral fraction of the crude extract led to the isolation of lupeol (1) and its three new long-chain fatty acid ester derivatives, namely, 3-O-(3'-hydroxyeicosanoyl)lupeol (2), 3-O-[(2'-(tetracosyloxy)acetyl]lupeol (3), and 3-O-[(1' '-hydroxyoctadecyloxy)-2'-hydroxypropanoyl]lupeol (4). These new compounds displayed some in vitro inhibition activity against the chloroquine-resistant strain FCR-3 isolated from Gambia and the chloroquine-sensitive standard strain 3D7. The hydroxy group of the fatty acid side chain appears to decrease the observed activity.