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Sample records for acetal benzoic acids

  1. The temperature dependence of the retention index for n-alkyl esters of acetic, propionic, cyclohexanecarboxylic, benzoic and phenylacetic acid on DB-1 and DB-5 capillary columns

    Directory of Open Access Journals (Sweden)

    DUSAN Z. MIJIN

    2006-06-01

    Full Text Available The temperature dependence of the retention index was studied for n-alkyl esters of acetic, propionic, cyclohexanecarboxylic, benzoic and phenylacetic acid on DB-1 and DB-5 capillary columns. The study was performed over various temperature ranges depending on the volatility of the ester. Two linear equations of the temperature dependence of the retention data on the column temperature and its reciprocal as variables were studied. Agood linearity of the retention index versus column temperature was found.

  2. [Selenazoles. XII. (1) Reaction of 4-(p-tolyl)-selenosemi-carbazides of acetic, benzoic, isonicotinic, nicotinic and picolinic acid with omega-acetophenone].

    Science.gov (United States)

    Biliński, S; Bielak, L; Chmielewski, J; Marcewicz-Rojewska, B; Musik, I

    1989-01-01

    The cyclization of 4-(p-tolyl)-selenosemicarbazides of acetic, benzoic, isonicotinic, nicotinic and picolinic acids (Ia-e) with omega-bromoacetophenone was investigated in the medium of methanol (Method A) or in methanol in the presence of anhydrous sodium acetate (Method B). Acid hydrolysis of compounds IIf-i and IVa-c, e was studied. Results of UV and IR spectrometric measurements and of the in vitro microbiological studies are presented. In contradistinction to corresponding thiosemicarbazides, the change in N4 nitrogen atom basicity of the parent selenosemicarbazide I (pKa of p-toluidine = 5.1), in comparison to that of 4-phenyl-selenosemicarbazide (pKa of aniline = 4.63), proved to influence the equilibrium of the reaction with omega-bromoacetophenone only in the methanol medium without addition of anhydrous sodium acetate (Method A).

  3. Acetylcholinesterase inhibitory properties of some benzoic acid derivatives

    Science.gov (United States)

    Yildiz, Melike; Kiliç, Deryanur; Ünver, Yaǧmur; Şentürk, Murat; Askin, Hakan; Küfrevioǧlu, Ömer Irfan

    2016-04-01

    Acetylcholinesterase (AChE) hydrolyses the neurotransmitter acetylcholine to acetic acid and choline. AChE inhibitors are used in treatment of several neurodegeneartive disorder and Alzheimer's disease. In the present study, inhibition of AChE with some benzoic acid derivatives were investigated. 3-Chloro-benzoic acid (1), 2-hydroxy-5-sulfobenzoic acid (2), 2-(sulfooxy) benzoic acid (3), 2-hydroxybenzoic acid (4), 2,3-dimethoxybenzoic (5), and 3,4,5-trimethoxybenzoic (6) were calculated IC50 values AChE enzyme. Kinetic investigations showed that similarly to AChE inhibitors. Benzoic acid derivatives (1-6) investigated are encouraging agents which may be used as lead molecules in order to derivative novel AChE inhibitors that might be useful in medical applications.

  4. Alteration of the phospho- or neutral lipid content and fatty acid composition in Listeria monocytogenes due to acid adaptation mechanisms for hydrochloric, acetic and lactic acids at pH 5.5 or benzoic acid at neutral pH.

    Science.gov (United States)

    Mastronicolis, Sofia K; Berberi, Anita; Diakogiannis, Ioannis; Petrova, Evanthia; Kiaki, Irene; Baltzi, Triantafillia; Xenikakis, Polydoros

    2010-10-01

    This study provides a first approach to observe the effects on Listeria monocytogenes of cellular exposure to acid stress at low or neutral pH, notably how phospho- or neutral lipids are involved in this mechanism, besides the fatty acid profile alteration. A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown at pH 5.5 in presence of hydrochloric, acetic and lactic acids, or at neutral pH 7.3 in presence of benzoic acid, is described relative to cells grown in acid-free medium. The results showed that only low pH values enhance the antimicrobial activity of an acid. We suggest that, irrespective of pH, the acid adaptation response will lead to a similar alteration in fatty acid composition [decreasing the ratio of branched chain/saturated straight fatty acids of total lipids], mainly originating from the neutral lipid class of adapted cultures. Acid adaptation in L. monocytogenes was correlated with a decrease in total lipid phosphorus and, with the exception of cells adapted to benzoic acid, this change in the amount of phosphorus reflected a higher content of the neutral lipid class. Upon acetic or benzoic acid stress the lipid phosphorus proportion was analysed in the main phospholipids present: cardiolipin, phosphatidylglycerol, phosphoaminolipid and phosphatidylinositol. Interestingly only benzoic acid had a dramatic effect on the relative quantities of these four phospholipids.

  5. Capillary Electrophoresis of Substituted Benzoic Acids

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    Mills, Nancy S.; Spence, John D.; Bushey, Michelle M.

    2005-01-01

    A series of substituted benzoic acids (SBAs) are prepared by students. The pKa shift, a result of the electron-withdrawing or electron-donating characteristics of the subsistent is examined in reference to the electrophoretic migration behavior of benzoic acid.

  6. 21 CFR 582.3021 - Benzoic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Benzoic acid. 582.3021 Section 582.3021 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives §...

  7. Estimated intake of benzoic and sorbic acids in Denmark

    DEFF Research Database (Denmark)

    Leth, Torben; Christensen, Tue; Larsen, I. K.

    2010-01-01

    for marmalade show some variation. Most foods in the categories soft drinks, dressings, fat-based salads, pickled herrings, and marmalade contain benzoic and sorbic acid, and sliced bread also contains in some cases sorbic acid. The median daily intake and intake distribution of benzoic and sorbic acids were......-old age group. Based on the average of all samples, the 95th percentile is over the acceptable daily intake for men up to 34 years and for women up to 24 years, and the 90th percentile for men up to 18 years and for women up to 10 years. Soft drinks, salads and dressings are the main contributors...... intakes of benzoic acid should not cause any concern for ill-effects. However, there must be a reason to reconsider the maximum limits especially for benzoic acid in soft drinks, dressings and salads and for sorbic acid in sliced bread....

  8. Inactivation of myeloperoxidase by benzoic acid hydrazide.

    Science.gov (United States)

    Huang, Jiansheng; Smith, Forrest; Panizzi, Jennifer R; Goodwin, Douglas C; Panizzi, Peter

    2015-03-15

    Myeloperoxidase (MPO) is expressed by myeloid cells for the purpose of catalyzing the formation of hypochlorous acid, from chloride ions and reaction with a hydrogen peroxide-charged heme covalently bound to the enzyme. Most peroxidase enzymes both plant and mammalian are inhibited by benzoic acid hydrazide (BAH)-containing compounds, but the mechanism underlying MPO inhibition by BAH compounds is largely unknown. Recently, we reported MPO inhibition by BAH and 4-(trifluoromethyl)-BAH was due to hydrolysis of the ester bond between MPO heavy chain glutamate 242 ((HC)Glu(242)) residue and the heme pyrrole A ring, freeing the heme linked light chain MPO subunit from the larger remaining heavy chain portion. Here we probed the structure and function relationship behind this ester bond cleavage using a panel of BAH analogs to gain insight into the constraints imposed by the MPO active site and channel leading to the buried protoporphyrin IX ring. In addition, we show evidence that destruction of the heme ring does not occur by tracking the heme prosthetic group and provide evidence that the mechanism of hydrolysis follows a potential attack of the (HC)Glu(242) carbonyl leading to a rearrangement causing the release of the vinyl-sulfonium linkage between (HC)Met(243) and the pyrrole A ring.

  9. Interaction Mechanism of Anthracene with Benzoic Acid and Its Derivatives

    Institute of Scientific and Technical Information of China (English)

    HE Ying-Ying; WANG Xiao-Chang; FAN Xiao-Yuan; ZHAO Bo; JIN Peng-Kang

    2008-01-01

    Interaction mechanism of anthracene, one of the typical polycyclic aromatic hydrocarbons, with benzoic acid and its hydroxyl-substituted derivatives, o-hydroxylbenzoic acid and p-hydroxylbenzoic acid, were studied using FFIR, UV and fluorescence spectra. The experiments confirmed that there was a specific and oriented interaction between anthracene and the aromatic carboxylic acids, and the bonding mode depended on both the chemical struc- ture of reactants and acidity of solution. The π-H hydrogen bond played a main role in the interaction between an-thracene and the aromatic carboxylic proton of benzoic acid or o-hydroxylbenzoic acid when pH≤pK, and the π-π electron donor-acceptor (EDA) interaction increasingly became the main binding mode when pH>pK. The de-crease of interaction intensity of benzoic acid was observed by introducing hydroxyl at its ortho position. The spe-cial D-π-A structure of p-hydroxylbenzoic acid made it easy to form the planar multi-molecule congeries that could interact with anthracene, so the interaction between anthracene and p-hydroxylbenzoic acid always followed the π-π EDA model no matter the solution acidity. For p-hydroxylbenzoic acid, the π-π interaction mode remained un-changed when pH increased from 2.0 to 10.0, and the binding intensity was higher than that between benzoic acid and anthracene because of the formation of the multi-molecule congeries.

  10. Antiparasitic activity of prenylated benzoic acid derivatives from Piper species.

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    Flores, Ninoska; Jiménez, Ignacio A; Giménez, Alberto; Ruiz, Grace; Gutiérrez, David; Bourdy, Genevieve; Bazzocchi, Isabel L

    2009-03-01

    Fractionation of dichloromethane extracts from the leaves of Piper heterophyllum and P. aduncum afforded three prenylated hydroxybenzoic acids, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid, 3-[(2E,6E,10E)-11-carboxy-13-hydroxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl]-4,5-dihydroxybenzoic acid and 3-[(2E,6E,10E)-11-carboxy-14-hydroxy-3,7,15-trimethyl-2,6,10,15-hexadecatetraenyl]-4,5-dihydroxybenzoic acid, along with the known compounds, 4,5-dihydroxy-3-(E,E,E-11-formyl-3,7,15-trimethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid (arieianal), 3,4-dihydroxy-5-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 4-hydroxy-3-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid, 4-hydroxy-3-(3,7-dimethyl-2,6-octadienyl)benzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. Riguera ester reactions and optical rotation measurements established the compounds as racemates. The antiparasitic activity of the compounds were tested against three strains of Leishmania spp., Trypanosoma cruzi and Plasmodium falciparum. The results showed that 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid exhibited potent and selective activity against L. braziliensis (IC(50) 6.5 microg/ml), higher that pentamidine used as control. Moreover, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl- 2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid showed moderate antiplasmodial (IC(50) 3.2 microg/ml) and trypanocidal (16.5 microg/ml) activities, respectively.

  11. A kinetic study on benzoic acid pungency and sensory attributes of benzoic acid.

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    Otero-Losada, M E

    1999-06-01

    Aqueous solutions of benzoic acid (BA) were evaluated by two methods: (i) sensory profile: a descriptive test of sensory attributes combined with semiquantitative analysis; and (ii) pungency intensity measures as a function of time: a computerized recording using specific software. Kinetic parameters evaluated were maximal intensity (I(MAX)), total time of pungency (Ttot), rates of increase (V1) and decrease (V2), half-life (T1/2), area under curve (AUC) and time to maximal intensity (T(IMAX)). Results were analyzed by ANOVA, LSD test, iterative calculations and adjustment to equations according to mathematical models, regression analysis, principal component analysis (PCA) and clusters analysis. Pungency was the main sensory attribute of BA (3-36 mM) in the tongue and epiglottis. The seven kinetic parameters showed concentration-dependency (P pungency intensity best correlated with both concentration and persistence among kinetic parameters. Prototypical prickling of BA was observed at 12 and 18 mM.

  12. Tramadol hydrochloride–benzoic acid (1/1

    Directory of Open Access Journals (Sweden)

    B. P. Siddaraju

    2011-09-01

    Full Text Available In the cation of the title co-crystal salt {systematic name: [2-hydroxy-2-(3-methoxyphenylcyclohexylmethyl]dimethylazanium chloride–benzoic acid (1/1}, C16H31NO2+·Cl−·C7H6O2, the N atom is protonated and the six-membered cyclohexane ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the benzene rings in the cation and the benzoic acid molecule is 75.5 (9°. The crystal packing is stabilized by weak intermolecular O—H...Cl, N—H...Cl and C—H...π interactions, forming a two-dimensional chain network along the b axis. The benzoic acid molecule is not involved in the usual head-to-tail dimer bonding, but instead is linked to the ammonium cation through mutual hydrogen-bonding interactions with the chloride anion.

  13. Benzoic Acid and Chlorobenzoic Acids: Thermodynamic Study of the Pure Compounds and Binary Mixtures With Water.

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    Reschke, Thomas; Zherikova, Kseniya V; Verevkin, Sergey P; Held, Christoph

    2016-03-01

    Benzoic acid is a model compound for drug substances in pharmaceutical research. Process design requires information about thermodynamic phase behavior of benzoic acid and its mixtures with water and organic solvents. This work addresses phase equilibria that determine stability and solubility. In this work, Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) was used to model the phase behavior of aqueous and organic solutions containing benzoic acid and chlorobenzoic acids. Absolute vapor pressures of benzoic acid and 2-, 3-, and 4-chlorobenzoic acid from literature and from our own measurements were used to determine pure-component PC-SAFT parameters. Two binary interaction parameters between water and/or benzoic acid were used to model vapor-liquid and liquid-liquid equilibria of water and/or benzoic acid between 280 and 413 K. The PC-SAFT parameters and 1 binary interaction parameter were used to model aqueous solubility of the chlorobenzoic acids. Additionally, solubility of benzoic acid in organic solvents was predicted without using binary parameters. All results showed that pure-component parameters for benzoic acid and for the chlorobenzoic acids allowed for satisfying modeling phase equilibria. The modeling approach established in this work is a further step to screen solubility and to predict the whole phase region of mixtures containing pharmaceuticals.

  14. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  15. Synthesis of p-(Di-n-propylsulphamyl Benzoic Acid

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    S. K. Shukla

    1968-10-01

    Full Text Available A process for the synthesis of p-carboxybenzene sulphonylchloride by oxidation of toluene-p-sulphonylchloride as well as toluene-p-sulphonic acid has been developed. p-carboxybenzene sulphonylchloride on condensation with di-n-propylamine yield p-(di-n-propylsulphamyl -benzoic acid, an uricusuric agent employed in chronic gouty arthritis and used as an antiuric adjuvant known in trade as "Benemid, Probenecid".

  16. Involvement of snapdragon benzaldehyde dehydrogenase in benzoic acid biosynthesis.

    Science.gov (United States)

    Long, Michael C; Nagegowda, Dinesh A; Kaminaga, Yasuhisa; Ho, Kwok Ki; Kish, Christine M; Schnepp, Jennifer; Sherman, Debra; Weiner, Henry; Rhodes, David; Dudareva, Natalia

    2009-07-01

    Benzoic acid (BA) is an important building block in a wide spectrum of compounds varying from primary metabolites to secondary products. Benzoic acid biosynthesis from L-phenylalanine requires shortening of the propyl side chain by two carbons, which can occur via a beta-oxidative pathway or a non-beta-oxidative pathway, with benzaldehyde as a key intermediate. The non-beta-oxidative route requires benzaldehyde dehydrogenase (BALDH) to convert benzaldehyde to BA. Using a functional genomic approach, we identified an Antirrhinum majus (snapdragon) BALDH, which exhibits 40% identity to bacterial BALDH. Transcript profiling, biochemical characterization of the purified recombinant protein, molecular homology modeling, in vivo stable isotope labeling, and transient expression in petunia flowers reveal that BALDH is capable of oxidizing benzaldehyde to BA in vivo. GFP localization and immunogold labeling studies show that this biochemical step occurs in the mitochondria, raising a question about the role of subcellular compartmentalization in BA biosynthesis.

  17. 3-[4-(Acetamidobenzenesulfonamido]benzoic acid

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    Muhammad Shafiq

    2011-01-01

    Full Text Available In the title compound, C15H14N2O5S, the dihedral angle between the aromatic rings is 63.20 (11 Å. The crystal structure displays classical intermolecular O—H...O hydrogen bonding typical for carboxylic acids, forming centrosymmetric dimers. These dimers are further connected by N—H...O and C—H...O hydrogen bonds to form an extended network.

  18. Benzoic acid derivatives from Piper species and their fungitoxic activity against Cladosporium cladosporioides and C. sphaerospermum.

    Science.gov (United States)

    Lago, João Henrique G; Ramos, Clécio Sousa; Casanova, Diego Campos C; Morandim, Andreia de A; Bergamo, Debora Cristina B; Cavalheiro, Alberto J; Bolzani, Vanderlan da S; Furlan, Maysa; Guimarães, Elsie F; Young, Maria Claudia M; Kato, Massuo J

    2004-11-01

    Piper crassinervium, P. aduncum, P. hostmannianum, and P. gaudichaudianum contain the new benzoic acid derivatives crassinervic acid (1), aduncumene (8), hostmaniane (18), and gaudichaudianic acid (20), respectively, as major secondary metabolites. Additionally, 19 known compounds such as benzoic acids, chromenes, and flavonoids were isolated and identified. The antifungal activity of these compounds was evaluated by bioautographic TLC assay against Cladosporium cladosporioides and C. sphaerospermum.

  19. Variable Temperature Infrared Spectroscopy Investigations of Benzoic Acid Desorption from Sodium and Calcium Montmorillonite Clays.

    Science.gov (United States)

    Nickels, Tara M; Ingram, Audrey L; Maraoulaite, Dalia K; White, Robert L

    2015-12-01

    Processes involved in thermal desorption of benzoic acid from sodium and calcium montmorillonite clays are investigated by using variable temperature diffuse reflection Fourier transform infrared spectroscopy (DRIFTS). By monitoring the temperature dependence of infrared absorbance bands while heating samples, subtle changes in molecular vibrations are detected and employed to characterize specific benzoic acid adsorption sites. Abrupt changes in benzoic acid adsorption site properties occur for both clay samples at about 125 °C. Difference spectra absorbance band frequency variations indicate that adsorbed benzoic acid interacts with interlayer cations through water bridges and that these interactions can be disrupted by the presence of organic anions, in particular, benzoate.

  20. QSBR study of substituted phenols and benzoic acids

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The biodegradability of 30 substituted phenols and benzoic acids was determined by BOD technique. The molecular weight (MW), heat of formation (Hf) and the energy of the highest occupied molecular orbital (EHOMO) of the studied compounds were calculated by the quantum chemical method MOPAC6.0-AM1. The quantitative structure-biodegradability relationships (QSBRs) were developed by the linear regression method and neural network approach, respectively. It has been shown that the neural network method is able to provide a superior fit to the training set data and test se t data and produce a lower prediction error than the linear regression method.

  1. Antiherbivore prenylated benzoic acid derivatives from Piper kelleyi.

    Science.gov (United States)

    Jeffrey, Christopher S; Leonard, Michael D; Glassmire, Andrea E; Dodson, Craig D; Richards, Lora A; Kato, Massuo J; Dyer, Lee A

    2014-01-24

    The known prenylated benzoic acid derivative 3-geranyl-4-hydroxy-5-(3″,3″-dimethylallyl)benzoic acid (1) and two new chromane natural products were isolated from the methanolic extract of the leaves of Piper kelleyi Tepe (Piperaceae), a midcanopy tropical shrub that grows in lower montane rain forests in Ecuador and Peru. Structure determination using 1D and 2D NMR analysis led to the structure of the chromene 2 and to the reassignment of the structure of cumanensic acid as 4, an isomeric chromene previously isolated from Piper gaudichaudianum. The structure and relative configuration of new chromane 3 was determined using 1D and 2D NMR spectroscopic analysis and was found to be racemic by ECD spectropolarimetry. The biological activity of 1-3 was evaluated against a lab colony of the generalist caterpillar Spodoptera exigua (Noctuidae), and low concentrations of 2 and 3 were found to significantly reduce fitness. Further consideration of the biosynthetic relationship of the three compounds led to the proposal that 1 is converted to 2 via an oxidative process, whereas 3 is produced through hetero-[4+2] dimerization of a quinone methide derived from the chromene 2.

  2. Absorption and metabolism of benzoic acid in growing pigs

    DEFF Research Database (Denmark)

    Kristensen, N B; Nørgaard, J V; Wamberg, S

    2009-01-01

    Dietary benzoic acid (BA) supplementation causes a pronounced reduction in urinary pH but only small changes in blood pH. The present study aimed to investigate the portal absorption profile, hepatic metabolism of BA, and renal excretion of hippuric acid (HA) underlying the relatively small impact...... of BA on systemic acid-base status. Eight growing pigs (BW = 63 ± 1 kg at sampling) fitted with permanent indwelling catheters in the abdominal aorta, hepatic portal vein, hepatic vein, and mesenteric vein were allocated to 4 sampling blocks and randomly assigned to control (CON; nonsupplemented diet...... portal flux and hepatic uptake of BA was 87 ± 5% and 89 ± 15%, respectively. The recovery of dietary BA as urinary excretion of BA and HA was 0.08 ± 0.02% and 85 ± 7%, respectively. It is concluded that the small impact of BA supplementation on systemic acid-base status was caused by a protracted BA...

  3. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup;

    2014-01-01

    of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  4. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  5. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  6. Infrared Spectroscopy of Hydrogen Bonds in Benzoic Acid Derivatives

    Science.gov (United States)

    Tolstorozhev, G. B.; Bel‧kov, M. V.; Skornyakov, I. V.; Bazyl, O. K.; Artyukhov, V. Ya.; Mayer, G. V.; Shadyro, O. I.; Kuzovkov, P. V.; Brinkevich, S. D.; Samovich, S. N.

    2014-03-01

    We have measured the Fourier transform IR spectra of CCl4 solutions of benzoic acid and its biologically active derivatives. We investigated the proton-acceptor properties of the studied molecules theoretically by the molecular electrostatic potential method. The calculations are compared with experimental results. Based on an estimate of the proton-acceptor properties, we give an interpretation of the specific features of the IR spectra of benzoic acid and its derivatives in the region of the O-H and C = O vibrations. The mechanisms for interactions of the molecules are determined by the nature of substituents which are added to the benzene ring in positions para and meta to the carboxyl group. We identify the conditions for appearance of intermolecular hydrogen bonds of O-H · · · O = C, O-H · · · O-H types with formation of cyclic and linear dimers. We show that intramolecular hydrogen bonds of the type O-H · · · O-CH3 prevent the hydroxyl groups from participating in intermolecular interactions.

  7. Effects of benzoic acid and cadmium toxicity on wheat seedlings

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    Kavita Yadav

    2013-06-01

    Full Text Available Benzoic acid (BA and Cd exhibit cumulative effects on plants due to their accumulation in the soil. The present study reports the effects of BA an allelochemical, Cd and their combinations on seed germination, seedling growth, biochemical parameters, and response of antioxidant enzymes in Triticum aestivum L. The experiment was conducted in sand supplemented with Hoagland nutrient solution. Benzoic acid was applied at concentrations of 0.5, 1.0, and 1.5 mM with or without Cd (7 mg L-1 to observe effects of allelochemical and Cd alone and in combination on wheat. Both stresses exhibited inhibitory effect on growth and metabolism of wheat seedlings. The allelochemical in single and combined treatments with Cd decreased seedling growth as compared to Cd stress. The two stresses significantly enhanced malondialdehyde content of wheat seedlings. The activity of other antioxidant enzymes, viz. superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase (APX, and guaiacol peroxidase (POX were also recorded. SOD increased in seedlings under the two stresses. CAT more prominently ameliorates the toxic effects of H2O2 as compared with APX and POX and protected wheat seedlings from oxidative stress. Allelochemical buttressed the toxic effect of Cd on wheat seedlings.

  8. An Optical Test Strip for the Detection of Benzoic Acid in Food

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    Fatimah Abu Bakar

    2011-07-01

    Full Text Available Fabrication of a test strip for detection of benzoic acid was successfully implemented by immobilizing tyrosinase, phenol and 3-methyl-2-benzothiazolinone hydrazone (MBTH onto filter paper using polystyrene as polymeric support. The sensing scheme was based on the decreasing intensity of the maroon colour of the test strip when introduced into benzoic acid solution. The test strip was characterized using optical fiber reflectance and has maximum reflectance at 375 nm. It has shown a highly reproducible measurement of benzoic acid with a calculated RSD of 0.47% (n = 10. The detection was optimized at pH 7. A linear response of the biosensor was obtained in 100 to 700 ppm of benzoic acid with a detection limit (LOD of 73.6 ppm. At 1:1 ratio of benzoic acid to interfering substances, the main interfering substance is boric acid. The kinetic analyses show that, the inhibition of benzoic is competitive inhibitor and the inhibition constant (Ki is 52.9 ppm. The activity of immobilized tyrosinase, phenol, and MBTH in the test strip was fairly sustained during 20 days when stored at 3 °C. The developed test strip was used for detection of benzoic acid in food samples and was observed to have comparable results to the HPLC method, hence the developed test strip can be used as an alternative to HPLC in detecting benzoic acid in food products.

  9. Isoniazid cocrystals with anti-oxidant hydroxy benzoic acids

    Science.gov (United States)

    Mashhadi, Syed Muddassir Ali; Yunus, Uzma; Bhatti, Moazzam Hussain; Tahir, Muhammad Nawaz

    2014-11-01

    Isoniazid is the primary constituent of “triple therapy” used to effectively treat tuberculosis. In tuberculosis and other diseases, tissue inflammation and free radical burst from macrophages results in oxidative stress. These free radicals cause pulmonary inflammation if not countered by anti-oxidants. Therefore, in the present study cocrystals of isoniazid with four anti-oxidant hydroxy benzoic acids have been reported. Gallic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, and 3-hydroxybenzoic acid resulted in the formation of cocrystals when reacted with isoniazid. Cocrystal structure analysis confirmed the existence of pyridine-carboxylic acid synthon in the cocrystals of isoniazid with Gallic acid, 2,3-dihydroxybenzoic acid and 3-hydroxybenzoic acid. While cocrystal of 3,5-dihydroxybenzoic acid formed the pyridine-hydroxy group synthon. Other synthons of different graph sets are formed between hydrazide group of isoniazid and coformers involving Nsbnd H⋯O and Osbnd H⋯N bonds. All the cocrystals were in 1:1 stoichiometric ratio.

  10. Effect of benzoic acid supplementation on acid-base status and mineralmetabolism in catheterized growing pigs

    DEFF Research Database (Denmark)

    Nørgaard, Jan Værum; Fernández, José Adalberto; Sørensen, Kristina Ulrich;

    2010-01-01

    Benzoic acid (BA) in diets for growing pigs results in urinary acidification and reduced ammonia emission. The objective was to study the impact of BA supplementation on the acid-base status and mineral metabolism in pigs. Eight female 50-kg pigs, fitted with a catheter in the abdominal aorta, were...

  11. Caldensinic acid, a benzoic acid derivative and others compounds from Piper carniconnectivum

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Harley da Silva; Souza, Maria de Fatima Vanderlei de; Chaves, Maria Celia de Oliveira, E-mail: cchaves@ltf.ufpb.b [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica

    2010-07-01

    A benzoic acid derivative - caldensinic acid, E-phythyl hexadecanoate, {beta}-sitosterol and stigmasterol mixture and phaeophytin a were isolated from the aerial parts of Piper carniconnectivum. The structures of these compounds were established unambiguously by IR, MS, 1D and 2D NMR analysis. (author)

  12. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 20, Revision 3 (FGE.20Rev3): Benzyl alcohols, benzaldehydes, a related acetal, benzoic acids, and related esters from chemical groups 23 and 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider in this revision 3 of Flavouring Group Evaluation 20, the SCF Opinion on benzoic acid. Furthermore information on stereoisomeric composition for two substa...

  13. Antibiofilm Properties of Acetic Acid

    Science.gov (United States)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378

  14. Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 μg/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01μg@mL-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations.

  15. Effect of Magnetite Nano Particles on p-n-Alkyl Benzoic Acid Mesogens

    Directory of Open Access Journals (Sweden)

    S. Sreehari Sastry

    2012-01-01

    Full Text Available The magnetite (Fe3O4 nanoparticles (0.5 wt% of size less than 20 nm doped in p-n-alkyl benzoic acids where n varies from heptyl (7 to nonyl (9 are prepared and the presence of Fe+3 is confirmed through UV-Visible spectrophotometer. Textural and phase transition temperature studies are carried out using polarizing optical microscopy on pure and nano doped p-n-alkyl benzoic acids. These results are further confirmed by DSC at a scan rate of 5ºC/min and dielectric studies. Dielectric studies are carried out, in which the variation of dielectric constant, loss and the conductivity are analyzed with respect to temperatures and frequencies. Increment of relaxation times for nano doped heptyl and nonyl benzoic acids are observed which implies that the dielectric nature is strengthened for the nano doped mesogens. The preference of nano doped p-n-alkyl benzoic acids is discussed.

  16. PRENYLATED BENZOIC ACID DERIVATIVES FROM PIPER SPECIES AS SOURCE OF ANTI-INFECTIVE AGENTS

    OpenAIRE

    2012-01-01

    A number of prenylated benzoic acids derivatives with interesting biological activities have been previously isolated and characterized from different species of piperaceae family. Several Piper species contained structurally similar compounds with diverse biological activities such as anti-bacterial, anti-fungal, insecticidal as well as anti-parasitic all of which produces compounds that can be classified as prenylated benzoic acid derivatives. Piper sp has proven to serve as a source of pot...

  17. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  18. Catalytic Ring Hydrogenation of Benzoic Acid with Supported Transition Metal Catalysts in scCO2

    OpenAIRE

    2007-01-01

    The ring hydrogenation of benzoic acid to cyclohexanecarboxylic acid over charcoal-supported transition metal catalysts in supercritical CO2 medium has been studied in the present work. The cyclohexanecarboxylic acid can be produced efficiently in supercritical CO2 at the low reaction temperature of 323 K. The presence of CO2 increases the reaction rate and several parameters have been discussed.

  19. Catalytic Ring Hydrogenation of Benzoic Acid with Supported Transition Metal Catalysts in scCO2

    Directory of Open Access Journals (Sweden)

    Fengyu Zhao

    2007-07-01

    Full Text Available The ring hydrogenation of benzoic acid to cyclohexanecarboxylic acid overcharcoal-supported transition metal catalysts in supercritical CO2 medium has been studiedin the present work. The cyclohexanecarboxylic acid can be produced efficiently insupercritical CO2 at the low reaction temperature of 323 K. The presence of CO2 increasesthe reaction rate and several parameters have been discussed.

  20. Preliminary Study on Benzoic Acid Adsorption from Crude Active Coals and Bentonite

    Directory of Open Access Journals (Sweden)

    Abbes Boucheta

    2016-04-01

    Full Text Available We studied the adsorption of pollutant benzoic acid by the modified bentonite of Maghnia (west of Algeria, and coal (Coal from the mines, southwest of Algeria, Bechar area under three forms, crude and activated. Kinetic data show that the balance of bentonite (as amended adsorbs organic acids better than activated and raw coal. Indeed, the intercalation of bentonite with benzoic acid causes an improvement in the texture of porous material, which allows its use in the adsorption of organic compounds. The adsorption isotherms (Langmuir and Freundlich indicate that the adsorption of benzoic acid by the coal and bentonite yielded results favorably. The results obtained showed the practical value of using the activated coal and bentonite (as amended in the field of remediation of water contaminated with organic pollutants

  1. PRENYLATED BENZOIC ACID DERIVATIVES FROM PIPER SPECIES AS SOURCE OF ANTI-INFECTIVE AGENTS

    Directory of Open Access Journals (Sweden)

    Ibrahim Malami

    2012-06-01

    Full Text Available A number of prenylated benzoic acids derivatives with interesting biological activities have been previously isolated and characterized from different species of piperaceae family. Several Piper species contained structurally similar compounds with diverse biological activities such as anti-bacterial, anti-fungal, insecticidal as well as anti-parasitic all of which produces compounds that can be classified as prenylated benzoic acid derivatives. Piper sp has proven to serve as a source of potential anti-infective agents by developing a biosynthetic route to the synthesis of prenylated benzoic acids derivative natural products as their chemical defense system. Despite the frequent isolation of these interesting compounds with strong biological activity, yet none have been taking into consideration for development into therapeutic agents.

  2. A More Challenging Interpretative Nitration Experiment Employing Substituted Benzoic Acids and Acetanilides

    Science.gov (United States)

    Treadwell, Edward M.; Lin, Tung-Yin

    2008-01-01

    An experiment is described involving the nitration of ortho or meta monosubstituted benzoic acids (XC[subscript 6]H[subscript 4]CO[subscript 2]H, X = Halogen, Me, OH, or OMe) and monochlorinated acetanilides with nitric acid to determine the regioselectivity of addition by [superscript 1]H NMR spectroscopy and molecular modeling. Students were…

  3. 21 CFR 582.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  4. Placental passage of benzoic acid, caffeine, and glyphosate in an ex vivo human perfusion system

    DEFF Research Database (Denmark)

    Mose, Tina; Kjaerstad, Mia Birkhoej; Mathiesen, Line

    2008-01-01

    group of compounds. Benzoic acid, caffeine, and glyphosate were chosen as model compounds because they are small molecules with large differences in physiochemical properties. Caffeine crossed the placenta by passive diffusion. The initial transfer rate of benzoic acid was more limited in the first part...... of the perfusion compared to caffeine, but reached the same steady-state level by the end of perfusion. The transfer of glyphosate was restricted throughout perfusion, with a lower permeation rate, and only around 15% glyphosate in maternal circulation crossed to the fetal circulation during the study period....

  5. EXTRACTION AND SORPTION BENZOIC ACID FROM AQUEOUS SOLUTIONS OF POLYMERS BASED ON N-VINYLAMIDES

    Directory of Open Access Journals (Sweden)

    A. G. Savvina

    2015-01-01

    Full Text Available The widespread use of aromatic acids (benzoic acid, salicylic as preservatives necessitates their qualitative and quantitative determination in food. Effective and common way to separation and concentration of aromatic acids liquid extraction. Biphasic system of water-soluble polymers based on (poly-N-vinyl pyrrolidone, and poly-N-vinylcaprolactam satisfy the requirements of the extraction system. When sorption concentration improved definition of the metrological characteristics, comply with the requirements for sensitivity and selectivity definition appears possible, use of inexpensive and readily available analytical equipment. When studying the adsorption of benzoic acid used as a sorbent crosslinked polymer based on N-vinyl pyrrolidone, obtained by radical polymerisation of a functional monomer and crosslinker. In the extraction of benzoic acid to maximize the allocation of water and the organic phase of the polymer used salt solutions with concentrations close to saturation. Regardless of the nature of the anion salt is used as salting-out agent, aromatic acids sorption increases with the size of the cations. In the experiment the maximum recovery rate (80% benzoic acid obtained in the PVP (0.2 weight%. Ammonium sulphate. The dependence stepepni benzoic acid extraction from time sorption sorbent mass and the pH of the aqueous phase. To establish equilibrium in the system, for 20 minutes. The dependence of the degree of extraction of the acid pH indicates that the acid is extracted into the molecular form. The maximum adsorption is reached at pH 3,5, with its efficiency decreases symbatically reduce the amount of undissociated acid molecules in solution.

  6. Optical Dephasing in a Glass-like System : A Photon Echo Study of Pentacene in Benzoic Acid

    NARCIS (Netherlands)

    Duppen, Koos; Molenkamp, Laurens W.; Morsink, Jos B.W.; Wiersma, Douwe A.; Trommsdorff, H.P.

    1981-01-01

    Optical absorption and picosecond photon echo experiments are used to study the dephasing of pentacene in benzoic acid. It is shown that, while the absorption spectrum of pentacene is effected by proton transfer in the benzoic acid dimer, the dephasing is caused by elastic and inelastic phonon scatt

  7. Syntheses,characteristics,and fluorescence properties of complexes of europium with benzoic acid and its derivatives

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhongcheng; SHU Wangen; RUAN Jianming; HUANG Boyun; LIU Younian

    2004-01-01

    The binary complexes of europium with benzoic acid and its derivatives (phthalic acid, m-phthalic acid,o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses. UV and IR of the complexes have been investigated. The UV spectra indicated that the complexes' ultraviolet absorption were mainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are different from those of free ligands. The fluorescence properties of them were investigated by using luminescence spectroscopy, the results showed that only three complexes appear as better luminescence, they were Eu-benzoic acid,Eu-m-phthalic acid and Eu-phthalic acid, while the others exhibited the ligands' wideband emission.

  8. Simultaneous determination of preservatives (benzoic acid, sorbic acid, methylparaben and propylparaben) in foodstuffs using high-performance liquid chromatography.

    Science.gov (United States)

    Saad, Bahruddin; Bari, Md Fazlul; Saleh, Muhammad Idiris; Ahmad, Kamarudzaman; Talib, Mohd Khairuddin Mohd

    2005-05-06

    A reversed-phased HPLC method that allows the separation and simultaneous determination of the preservatives benzoic (BA) and sorbic acids (SA), methyl- (MP) and propylparabens (PP) is described. The separations were effected by using an initial mobile phase of methanol-acetate buffer (pH 4.4) (35:65) to elute BA, SA and MP and changing the mobile phase composition to methanol-acetate buffer (pH 4.4) (50:50) thereafter. The detector wavelength was set at 254 nm. Under these conditions, separation of the four components was achieved in less than 23 min. Analytical characteristics of the separation such as limit of detection, limit of quantification, linear range and reproducibility were evaluated. The developed method was applied to the determination of 67 foodstuffs (mainly imported), comprising soft drinks, jams, sauces, canned fruits/vegetables, dried vegetables/fruits and others. The range of preservatives found were from not detected (nd)--1260, nd--1390, nd--44.8 and nd--221 mg kg(-1) for BA, SA, MP and PP, respectively.

  9. Extractive fermentation of acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Busche, R.M. [Bio En-Gene-Er Associates, Inc., Wilmington, DE (United States)

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  10. In vitro skin absorption and metabolism of benzoic acid, p-aminobenzoic acid, and benzocaine in the hairless guinea pig.

    Science.gov (United States)

    Nathan, D; Sakr, A; Lichtin, J L; Bronaugh, R L

    1990-11-01

    The percutaneous absorption and metabolism of three structurally related compounds, benzoic acid, p-aminobenzoic acid (PABA), and ethyl aminobenzoate (benzocaine), were determined in vitro through hairless guinea pig skin. Benzocaine was also studied in human skin. Absorption of benzocaine was rapid and similar through both viable and nonviable skin. The absorption of the two acidic compounds, benzoic acid and PABA, was greater through nonviable skin. A small portion (6.9%) of absorbed benzoic acid was conjugated with glycine to form hippuric acid. Although N-acetyl-benzocaine had not been observed as a metabolite of benzocaine when studied by other routes of administration, both PABA and benzocaine were extensively N-acetylated during percutaneous absorption. Thus, the metabolism of these compounds should be considered in an accurate assessment of absorption after topical application.

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

    Science.gov (United States)

    2010-07-01

    ...)amino-, methyl ester. 721.1728 Section 721.1728 Protection of Environment ENVIRONMENTAL PROTECTION...-, methyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is...

  12. Deoxygenation of benzoic acid on metal oxides. 2. Formation of byproducts.

    NARCIS (Netherlands)

    de Lange, M.W.; van Ommen, J.G.; Lefferts, Leonardus

    2002-01-01

    Benzene, benzophenone, toluene and benzylalcohol are byproducts in the selective deoxygenation of benzoic acid to benzaldehyde on ZnO and ZrO2. In this paper, the pathways to the byproducts are discussed and a complete overview of the reaction network is presented. Benzene and benzophenone are produ

  13. Comparative thermodynamic study on complex formation of native and hydroxypropylated cyclodextrins with benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Terekhova, Irina V., E-mail: ivt@isc-ras.ru [Institute of Solution Chemistry of RAS, Ivanovo (Russian Federation)

    2011-11-10

    Highlights: Black-Right-Pointing-Pointer Comparative calorimetric study on complexation of benzoic acid by native and modified cyclodextrins was performed. Black-Right-Pointing-Pointer Van der Waals interactions are responsible for complex formation with {alpha}-cyclodextrins. Black-Right-Pointing-Pointer Complex formation of {beta}-cyclodextrins is governed by dehydration and hydrophobic interactions. Black-Right-Pointing-Pointer Binding of two benzoic acid molecules by {gamma}-cyclodextrins is driven by van der Waals interactions and solvent reorganization. Black-Right-Pointing-Pointer Hydroxypropyl groups favor binding of benzoic acid only with hydroxypropyl-{beta}-cyclodextrin. - Abstract: Complex formation of native and hydroxypropylated {alpha}-, {beta}- and {gamma}-cyclodextrins with benzoic acid in water was studied by means of calorimetry of solution at 298.15 K. The 1:1 complexes are formed with {alpha}- and {beta}-cyclodextrins, while 1:2 binding stoichiometry was observed for {gamma}-cyclodextrins. Thermodynamic parameters of complex formation of hydroxypropylated cyclodextrins were determined for the first time and analyzed. Comparison of binding affinity of native and modified cyclodextrins was carried out.

  14. 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.

  15. Correlation between chemical structure and rodent repellency of benzoic acid derivatives

    Science.gov (United States)

    Fearn, J.E.; DeWitt, J.B.

    1965-01-01

    Sixty-five benzoic acid derivatives were either prepared or obtained from commercial concerns, tested for rat repellency, and their indices of repellency computed. The data from these tests were considered analytically for any correlation between chemical structure and rat repellency. The results suggest a qualitative relationship which is useful in deciding probability of repellency in other compounds.

  16. A new flavonoid with a benzoic acid substituent from Selaginella uncinata

    Institute of Scientific and Technical Information of China (English)

    Jun Xia Zheng; Nai Li Wang; Hao Gao; Hong Wei Liu; Hai Feng Chen; Ming Fan; Xin Sheng Yao

    2008-01-01

    6-(5-Carboxyl-2-methoxyphenyl)-apigenin (1), a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata (Desv.) Spring. Its structure was established by spectroscopic methods. Compound 1 represents the first example of the flavonoids possessing a benzoic acid substituent at C-6.

  17. Pharmacological Studies of p, N-(3, 4-Methylenedioxy phenyl Benzoic Acid (RRL-1364 - Part-I

    Directory of Open Access Journals (Sweden)

    Dahanukar Sharadini

    1978-01-01

    Full Text Available Detailed pharmacological investigations of p-N-(3, 4-methylene dioxy phenyl benzoic acid revealed marked hypotensive action which was dose dependent and most marked in cats; it was absent in rats. Atropine could block this hypotensive action, thus suggest-ing cholinomimetic mechanism. Further studies indicated that the hypotension produced was central and possibly medullary in origin.

  18. Deoxygenation of benzoic acid on metal oxides. 2. Formation of byproducts.

    NARCIS (Netherlands)

    Lange, de M.W.; Ommen, van J.G.; Lefferts, L.

    2002-01-01

    Benzene, benzophenone, toluene and benzylalcohol are byproducts in the selective deoxygenation of benzoic acid to benzaldehyde on ZnO and ZrO2. In this paper, the pathways to the byproducts are discussed and a complete overview of the reaction network is presented. Benzene and benzophenone are produ

  19. Deoxygenation of benzoic acid on metal oxides. I. The selective pathway to benzaldehyde

    NARCIS (Netherlands)

    Lange, de M.W.; Ommen, van J.G.; Lefferts, L.

    2001-01-01

    The mechanism of the selective deoxygenation of benzoic acid to benzaldehyde was studied on ZnO and ZrO2. The results show conclusively that the reaction proceeds as a reverse type of Mars and van Krevelen mechanism consisting of two steps: hydrogen activates the oxide by reduction resulting in the

  20. 21 CFR 184.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  1. Imidazolium ionic liquid-supported sulfonic acids: Efficient and recyclable catalysts for esterification of benzoic acid

    Institute of Scientific and Technical Information of China (English)

    Yue Qin Cai; Guo Qiang Yu; Chuan Duo Liu; Yuan Yuan Xu; Wei Wang

    2012-01-01

    Several imidazolium ionic liquid (IL)-supported sulfonic acids with different anions,[C3SO3Hmim]HSO4,[C3SO3Hmim]BF4,[C3SO3Hmim]PF6,and [C3SO3Hmim]CF3SO3,were synthesized and applied as catalysts for esterification reaction of benzoic acid.The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO4- shows the best catalytic activity.Only when less [C3SO3Hmim]HSO4 (0.3 equiv.) applied,was the product obtained with high yield of 97%.Furthermore,the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.

  2. Urine acidification and mineral metabolism in growing pigs feddiets supplemented with dietary methionine and benzoic acid

    DEFF Research Database (Denmark)

    Nørgaard, Jan Værum; Fernández, José Adalberto; Eriksen, Jørgen

    2010-01-01

    Benzoic acid (BA) reduces pH of urine and thereby reduces the emission of ammonia and possibly also odorous sulphur-compounds from slurry. The effect of BA on mineral metabolism in growing pigs is not clear. The objective was therefore to study the effect of BA and methionine (Met) as a sulphur (S...... d adaptation period and a 7 d period with collection of faeces and urine. Benzoic acid was metabolized into hippuric acid which reduced urinary pH by 0.8 pH units (P ... apparent digestibility was not (P = 0.58) affected by BA, but on the 1% Met diets, S excretion into urine was reduced (P = 0.006) by BA. In conclusion, both BA and Met supplementation increased P and Ca apparent digestibility and decreased urinary pH. The increased acid load provided through dietary BA did...

  3. Dietary exposure estimates for the food preservatives benzoic acid and sorbic acid in the total diet in Taiwan.

    Science.gov (United States)

    Ling, Min-Pei; Lien, Keng-Wen; Wu, Chiu-Hua; Ni, Shih-Pei; Huang, Hui-Ying; Hsieh, Dennis P H

    2015-02-25

    The purpose was to assess the health risk to general consumers in Taiwan associated with dietary intake of benzoic acid and sorbic acid by conducting a total diet study (TDS). The hazard index (HI) in percent acceptable daily intake (%ADI) of benzoic acid and sorbic acid for eight exposure groups classified by age were calculated. In high-intake consumers, the highest HI of benzoic acid was 54.1%ADI for males aged 1-2 years old at the 95th percentile, whereas for females, the HI was 61.7%ADI for aged over 66 years old. The highest HI of sorbic acid for male and female consumers aged 3-6 years old at the 95th percentile were 14.0%ADI and 12.2%ADI, respectively. These results indicate that the use of benzoic acid and sorbic acid as preservatives at the current level of use in the Taiwanese diet does not constitute a public health and safety concern.

  4. Effects of culture conditions on acetic acid production by bacteria ...

    African Journals Online (AJOL)

    SARAH

    2015-11-30

    Nov 30, 2015 ... Keywords: Acetic acid bacteria, acetic acid production, Cocoa fermentation, culture conditions. INTRODUCTION ... assessed by acid forming colony characterized by a ... production capacity to ethanol, lactic acid, acetic acid.

  5. Distribution ratio, distribution constant and partition coefficient. Countercurrent chromatography retention of benzoic acid.

    Science.gov (United States)

    Berthod, Alain; Mekaoui, Nazim

    2011-09-09

    There is some confusion in chromatography between terms such as solute distribution ratio, distribution constant and partition coefficient. These terms are very precisely defined in the field of liquid-liquid systems and liquid-liquid extraction as well as in the field of chromatography with sometimes conflicting definitions. Countercurrent chromatography (CCC) is a chromatographic technique in which the stationary phase is a support-free liquid. Since the mobile phase is also liquid, biphasic liquid systems are used. This work focuses on the exact meaning of the terms since there are consequences on experimental results. The retention volumes of solutes in CCC are linearly related to their distribution ratios. The partition coefficient that should be termed (IUPAC recommendation) distribution constant is linked to a single definite species. Using benzoic acid that can dimerize in heptane and ionize in aqueous phase and an 18 mL hydrodynamic CCC column, the role and relationships between parameters and the consequences on experimental peak position and shape are discussed. If the heptane/water distribution constant (marginally accepted to be called partition coefficient) of benzoic acid is 0.2 at 20 °C and can be tabulated in books, its CCC measured distribution ratio or distribution coefficient can change between zero (basic aqueous mobile phase) and more than 25 (acidic aqueous mobile phase and elevated concentration). Benzoic acid distribution ratio and partition coefficient coincide only when both dimerization and ionization are quenched, i.e. at very low concentration and pH 2. It is possible to quench dimerization adding butanol in the heptane/water system. However, butanol additions also affect the partition coefficient of benzoic acid greatly by increasing it.

  6. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, Sascha R.A.; van der Ham, Aloysius G.J.; Schuur, Boelo

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  7. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, S.R.A.; Ham, van der A.G.J.; Schuur, B.

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  8. Direct Oxidation of Ethene to Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained with selectivity of 82.7% and once-through space time yield (STY) of 257.4 g/h×L.

  9. Substituent Effects on the Low-Frequency Vibrational Modes of Benzoic Acid and Related Compounds

    Institute of Scientific and Technical Information of China (English)

    GE Min; ZHAO Hong-Wei; WANG Wen-Feng; YU Xiao-Han; LI Wen-Xin

    2007-01-01

    Well-resolved absorption spectra of benzoic acid and its derivatives with one hydrogen atom replaced by a substituent group CH3, OH, NH2 or NO2 were reported in the frequency region between 6 and 67 cm-1 at room temperature with terahertz time-domain spectroscopy (THz-TDS). These substances can be distinguished easily based on the terahertz absorption spectra. The measurements suggested that even minor changes in the molecular configuration and chemical composition lead to distinct differences in THz spectrum. Density functional theory (DFT)method was used to assist the analysis and assignment of the individual THz absorption spectra of benzoic acid and its methyl derivatives. Observed THz responses of samples can be assigned to the collective vibrations associated with intermolecular hydrogen bonds.

  10. Mechanistic and Kinetic Insight into Spontaneous Cocrystallization of Isoniazid and Benzoic Acid.

    Science.gov (United States)

    Sarceviča, Inese; Orola, Liana; Nartowski, Karol P; Khimyak, Yaroslav Z; Round, Andrew N; Fábián, László

    2015-08-03

    Solid-state cocrystallization is of contemporary interest because it offers an easy and efficient way to produce cocrystals, which are recognized as prospective pharmaceutical materials. Research explaining solid-state cocrystallization mechanisms is important but still too scarce to give a broad understanding of factors governing and limiting these reactions. Here we report an investigation of the mechanism and kinetics of isoniazid cocrystallization with benzoic acid. This reaction is spontaneous; however, its rate is greatly influenced by environmental conditions (humidity and temperature) and pretreatment (milling) of the sample. The acceleration of cocrystallization in the presence of moisture is demonstrated by kinetic studies at elevated humidity. The rate dependence on humidity stems from moisture facilitated rearrangements on the surface of isoniazid crystallites, which lead to cocrystallization in the presence of benzoic acid vapor. Furthermore, premilling the mixture of the cocrystal ingredients eliminated the induction time of the reaction and considerably increased its rate.

  11. Screening of organic halogens and identification of chlorinated benzoic acids in carbonaceous meteorites.

    Science.gov (United States)

    Schöler, Heinz F; Nkusi, Gerard; Niedan, Volker W; Müller, German; Spitthoff, Bianca

    2005-09-01

    The occurrence of halogenated organic compounds measured as a sum parameter and the evidence of chlorinated benzoic acids in four carbonaceous meteorites (Cold Bokkeveld, Murray, Murchison and Orgueil) from four independent fall events is reported. After AOX (Adsorbable organic halogen) and EOX (Extractable organic halogen) screening to quantify organically bound halogens, chlorinated organic compounds were analyzed by gas chromatography. AOX concentrations varying from 124 to 209 microg Cl/g d.w. were observed in carbonaceous meteorites. Ion chromatographic analysis of the distribution of organically bound halogens performed on the Cold Bokkeveld meteorite revealed that chlorinated and brominated organic compounds were extractable, up to 70%, whereas only trace amounts of organofluorines could be extracted. Chlorinated benzoic acids have been identified in carbonaceous meteorite extracts. Their presence and concentrations raise the question concerning the origin of halogenated, especially chlorinated, organic compounds in primitive planetary matter.

  12. A Green Synthesis of 2-Ethylanthraquinone by Dehydration of 2-(4'-ethylbenzoyl) benzoic Acid over Solid Acid Catalysts

    Institute of Scientific and Technical Information of China (English)

    Ren Shu XU; Xin Wen GUO; Gui Ru WANG; Zhu Xia ZHANG

    2005-01-01

    The dehydration of 2-(4'-ethylbenzoyl) benzoic acid (BE acid) to 2-ethylanthraquinone(2-EAQ) was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 solution exhibited an excellent performance. In our study, theconversion of BE acid can reach 96.7%, and the selectivity to 2-EAQ is up to 99.6%.

  13. Molecular modeling study of para amino benzoic acids recognition by β-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Madi Fatiha

    2009-01-01

    Full Text Available AM1 and PM3 methods were applied to investigate equilibrium geometries of inclusion complexes formed between 3-CD and neutral, anionic and cationic species of PABA (Para amino benzoic acid. 3-CD can bind to these three species (two possible orientations A or B with negative binding energy, where the preference between A and Borientation of each PABA species is due to H-bond interaction. Finally, the HOMO and LUMO energies of each complex were calculated and compared.

  14. Immobilization of Tyrosinase from Avocado Crude Extract in Polypyrrole Films for Inhibitive Detection of Benzoic Acid

    Directory of Open Access Journals (Sweden)

    André Brisolari

    2014-07-01

    Full Text Available Inhibition-based biosensors were developed by immobilizing tyrosinase (Tyr, polyphenol oxidase from the crude extract of avocado fruit on electrochemically prepared polypyrrole (PPy films. The biosensors were prepared during the electropolymerization of pyrrole in a solution containing a fixed volume of the crude extract of avocado. The dependence of the biosensor responses on the volume used from the crude extract, values of pH and temperature was studied, and a substrate, catechol, at different concentrations, was amperometrically detected by these biosensors. Benzoic acid, a competitive inhibitor of Try, was added to the catechol solutions at specific concentrations aimed at obtaining the inhibition constant, K’m, which ranged from 1.7 to 4.6 mmol∙L−1 for 0.0 and 60 µmol∙L−1 of benzoic acid, respectively. Studies on the inhibition caused by benzoic acid by using PPy/Try films, and catechol as a substrate, allowed us propose how to develop, under optimized conditions, simple and low-cost biosensors based on the use of avocado fruit.

  15. Detection of Benzoic Acid by an Amperometric Inhibitor Biosensor Based on Mushroom Tissue Homogenate

    Directory of Open Access Journals (Sweden)

    Mustafa Kemal Sezgintürk

    2005-01-01

    Full Text Available An amperometric benzoic acid-sensing inhibitor biosensor was prepared by immobilizing mushroom (Agaricus bisporus tissue homogenate on a Clark-type oxygen electrode. The effects of the quantity of mushroom tissue homogenate, the quantity of gelatin and the effect of the crosslinking agent glutaraldehyde percent on the biosensor were studied. The optimum concentration of phenol used as substrate was 200 μM. The bioanalytical properties of the proposed biosensor, such as dependence of the biosensor response on the pH value and the temperature, were investigated. The biosensor responded linearly to benzoic acid in a concentration range of 25–100 μM. Standard deviation (s.d. was ±0.49 μM for 7 successive determinations at a concentration of 75 μM. The inhibitor biosensor based on mushroom tissue homogenate was applied for the determination of benzoic acid in fizzy lemonade, some fruits and groundwater samples. Results were compared to those obtained using AOAC method, showing a good agreement.

  16. Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology

    Science.gov (United States)

    Yoo, Mi-Young; Lim, Sang-Dong

    2016-01-01

    Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products. PMID:27433115

  17. Benzoic Acid Production with Respect to Starter Culture and Incubation Temperature during Yogurt Fermentation using Response Surface Methodology.

    Science.gov (United States)

    Yu, Hyung-Seok; Lee, Na-Kyoung; Jeon, Hye-Lin; Eom, Su Jin; Yoo, Mi-Young; Lim, Sang-Dong; Paik, Hyun-Dong

    2016-01-01

    Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

  18. Transcriptome analysis of acetic-acid-treated yeast cells identifies a large set of genes whose overexpression or deletion enhances acetic acid tolerance.

    Science.gov (United States)

    Lee, Yeji; Nasution, Olviyani; Choi, Eunyong; Choi, In-Geol; Kim, Wankee; Choi, Wonja

    2015-08-01

    Acetic acid inhibits the metabolic activities of Saccharomyces cerevisiae. Therefore, a better understanding of how S. cerevisiae cells acquire the tolerance to acetic acid is of importance to develop robust yeast strains to be used in industry. To do this, we examined the transcriptional changes that occur at 12 h post-exposure to acetic acid, revealing that 56 and 58 genes were upregulated and downregulated, respectively. Functional categorization of them revealed that 22 protein synthesis genes and 14 stress response genes constituted the largest portion of the upregulated and downregulated genes, respectively. To evaluate the association of the regulated genes with acetic acid tolerance, 3 upregulated genes (DBP2, ASC1, and GND1) were selected among 34 non-protein synthesis genes, and 54 viable mutants individually deleted for the downregulated genes were retrieved from the non-essential haploid deletion library. Strains overexpressing ASC1 and GND1 displayed enhanced tolerance to acetic acid, whereas a strain overexpressing DBP2 was sensitive. Fifty of 54 deletion mutants displayed enhanced acetic acid tolerance. Three chosen deletion mutants (hsps82Δ, ato2Δ, and ssa3Δ) were also tolerant to benzoic acid but not propionic and sorbic acids. Moreover, all those five (two overexpressing and three deleted) strains were more efficient in proton efflux and lower in membrane permeability and internal hydrogen peroxide content than controls. Individually or in combination, those physiological changes are likely to contribute at least in part to enhanced acetic acid tolerance. Overall, information of our transcriptional profile was very useful to identify molecular factors associated with acetic acid tolerance.

  19. 取代苯甲酸类化合物在正辛醇中的固液平衡%Solid-Liquid Equilibria of Benzoic Acid Derivatives in 1-Octanol

    Institute of Scientific and Technical Information of China (English)

    贾青竹; 马沛生; 马少娜; 王昶

    2007-01-01

    The solid-liquid equilibrium of benzoic acid derivatives in 1-octanol was first determined in this article.Using a laser monitoring observation technique, the solubility data of o-amino-benzoic acid, p-amino-benzoic acid,o-chloro-benzoic acid, and m-nitro-benzoic acid in 1-octanol were measured by the polythermal method in the temperature range of 20-50 ℃. The experimental data were regressed with the Wilson equation and the λH equation. The experimental results showed that the solubility of the four chemicals in 1-octanol increased significantly with temperature. The results indicate that the molecular structure and interactions affect the solubility significantly.The solubility order of the benzoic acid derivatives is as follows: m-nitro-benzoic acid>o-chloro-benzoic acid>o-amino-benzoic acid>p-amino-benzoic acid. Both the Wilson equation and λH equation are in good agreement with the experimental data.

  20. Acetobacter pasteurianus metabolic change induced by initial acetic acid to adapt to acetic acid fermentation conditions.

    Science.gov (United States)

    Zheng, Yu; Zhang, Renkuan; Yin, Haisong; Bai, Xiaolei; Chang, Yangang; Xia, Menglei; Wang, Min

    2017-08-02

    Initial acetic acid can improve the ethanol oxidation rate of acetic acid bacteria for acetic acid fermentation. In this work, Acetobacter pasteurianus was cultured in ethanol-free medium, and energy production was found to increase by 150% through glucose consumption induced by initial acetic acid. However, oxidation of ethanol, instead of glucose, became the main energy production pathway when upon culturing ethanol containing medium. Proteome assay was used to analyze the metabolism change induced by initial acetic acid, which provided insight into carbon metabolic and energy regulation of A. pasteurianus to adapt to acetic acid fermentation conditions. Results were further confirmed by quantitative real-time PCR. In summary, decreased intracellular ATP as a result of initial acetic acid inhibition improved the energy metabolism to produce more energy and thus adapt to the acetic acid fermentation conditions. A. pasteurianus upregulated the expression of enzymes related to TCA and ethanol oxidation to improve the energy metabolism pathway upon the addition of initial acetic acid. However, enzymes involved in the pentose phosphate pathway, the main pathway of glucose metabolism, were downregulated to induce a change in carbon metabolism. Additionally, the enhancement of alcohol dehydrogenase expression promoted ethanol oxidation and strengthened the acetification rate, thereby producing a strong proton motive force that was necessary for energy production and cell tolerance to acetic acid.

  1. Exposure assessment of food preservatives (sulphites, benzoic and sorbic acid) in Austria.

    Science.gov (United States)

    Mischek, Daniela; Krapfenbauer-Cermak, Christine

    2012-01-01

    An exposure assessment was performed to estimate the potential intake of preservatives in the Austrian population. Food consumption data of different population groups, such as preschool children aged 3-6 years, female and male adults aged 19-65 years were used for calculation. Levels of the preservatives in food were derived from analyses conducted from January 2007 to August 2010. Dietary intakes of the preservatives were estimated and compared to the respective acceptable daily intakes (ADIs). In the average-intake scenario, assuming that consumers randomly consume food products that do or do not contain food additives, estimated dietary intakes of all studied preservatives are well below the ADI for all population groups. Sulphite exposure accounted for 34%, 84% and 89% of the ADI in preschool children, females and males, respectively. The mean estimated daily intake of benzoic acid was 32% (preschool children), 31% (males) and 36% (females) of the ADI. Sorbic acid intakes correspond to 7% of the ADI in preschool children and 6% of the ADI in adults. In the high-intake scenario assuming that consumers always consume food products that contain additives and considering a kind of brand loyalty of consumers, the ADI is exceeded for sulphites among adults (119 and 124%, respectively). Major contributors to the total intake of sulphites were wine and dried fruits for adults. Mean estimated dietary intakes of benzoic acid exceeded the ADI in all population groups, 135% in preschool children, 124% in females and 118% of the ADI in males, respectively. Dietary intakes of sorbic acid are well below the ADI, accounting for a maximum of 30% of the ADI in preschool children. The highest contributors to benzoic and sorbic acid exposure were fish and fish products mainly caused by high consumption data of this large food group, including also mayonnaise-containing fish salads. Other important sources of sorbic acid were bread, buns and toast bread and fruit and vegetable

  2. Alkaline earth layered benzoates as reusable heterogeneous catalysts for the methyl esterification of benzoic acid

    Directory of Open Access Journals (Sweden)

    Swamy Arêa Maruyama

    2012-01-01

    Full Text Available This paper describes the synthesis and characterization of layered barium, calcium and strontium benzoates and evaluates the potential of these materials as catalysts in the synthesis of methyl benzoate. The methyl esterification of benzoic acid was investigated, where the effects of temperature, alcohol:acid molar ratio and amount of catalyst were evaluated. Ester conversions of 65 to 70% were achieved for all the catalysts under the best reaction conditions. The possibility of recycling these metallic benzoates was also demonstrated, evidenced by unaltered catalytic activity for three consecutive reaction cycles.

  3. A chromene and prenylated benzoic acid from Piper aduncum.

    Science.gov (United States)

    Baldoqui, D C; Kato, M J; Cavalheiro, A J; Bolzani, V da S; Young, M C; Furlan, M

    1999-08-01

    In addition to nerolidol, 2',6'-dihydroxy-4'-methoxydihydrochalcone, methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate, methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate and methyl 8-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate, two new natural products were isolated from the leaves of Piper aduncum, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid. The structures of the isolates were established based on analysis of spectroscopic data, including ES-MS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae.

  4. Crystal structure of 3-[(2-acetylphenoxycarbonyl]benzoic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Shoaib

    2014-11-01

    Full Text Available In the title compound, C16H12O5, synthesized from isopthaloyl chloride and 2′-hydroxyacetophenone, the dihedral angle between the planes of the aromatic rings is 71.37 (9°. In the crystal, carboxylic acid inversion dimers generate R22(8 loops. The dimers are linked by C—H...O interactions, generating (101 sheets.

  5. Acetic acid fermentation of acetobacter pasteurianus: relationship between acetic acid resistance and pellicle polysaccharide formation.

    Science.gov (United States)

    Kanchanarach, Watchara; Theeragool, Gunjana; Inoue, Taketo; Yakushi, Toshiharu; Adachi, Osao; Matsushita, Kazunobu

    2010-01-01

    Acetobacter pasteurianus strains IFO3283, SKU1108, and MSU10 were grown under acetic acid fermentation conditions, and their growth behavior was examined together with their capacity for acetic acid resistance and pellicle formation. In the fermentation process, the cells became aggregated and covered by amorphous materials in the late-log and stationary phases, but dispersed again in the second growth phase (due to overoxidation). The morphological change in the cells was accompanied by changes in sugar contents, which might be related to pellicle polysaccharide formation. To determine the relationship between pellicle formation and acetic acid resistance, a pellicle-forming R strain and a non-forming S strain were isolated, and their fermentation ability and acetic acid diffusion activity were compared. The results suggest that pellicle formation is directly related to acetic acid resistance ability, and thus is important to acetic acid fermentation in these A. pasteurianus strains.

  6. Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng, E-mail: zhxch@zzu.edu.cn

    2014-03-15

    MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H{sub 2}O{sub 2} indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions. Highlights: • 5–45 wt% HPW/MCM-48 mesoporous catalysts were prepared and characterized. • Their catalytic activities for the green synthesis of benzoic acid were investigated. • HPW/MCM-48 was approved to be an efficient catalyst. • 5 wt% HPW/MCM-48 exhibited the highest catalytic activity.

  7. Ordered cleavage of myeloperoxidase ester bonds releases active site heme leading to inactivation of myeloperoxidase by benzoic acid hydrazide analogs.

    Science.gov (United States)

    Huang, Jiansheng; Smith, Forrest; Panizzi, Peter

    2014-04-15

    Myeloperoxidase (MPO) catalyzes the breakdown of hydrogen peroxide and the formation of the potent oxidant hypochlorous acid. We present the application of the fluorogenic peroxidase substrate 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) in steady-state and transient kinetic studies of MPO function. Using initial kinetic parameters for the MPO system, we characterized under the same conditions a number of gold standards for MPO inhibition, namely 4-amino benzoic acid hydrazide (4-ABAH), isoniazid and NaN3 before expanding our focus to isomers of 4-ABAH and benzoic acid hydrazide analogs. We determined that in the presence of hydrogen peroxide that 4-ABAH and its isomer 2-ABAH are both slow-tight binding inhibitors of MPO requiring at least two steps, whereas NaN3 and isoniazid-based inhibition has a single observable step. We also determined that MPO inhibition by benzoic acid hydrazide and 4-(trifluoromethyl) benzoic acid hydrazide was due to hydrolysis of the ester bond between MPO heavy chain Glu 242 residue and the heme pyrrole A ring, freeing the light chain and heme b fragment from the larger remaining MPO heavy chain. This new mechanism would essentially indicate that the benzoic acid hydrazide analogs impart inhibition through initial ejection of the heme catalytic moiety without prior loss of the active site iron.

  8. Acetic acid mediated interactions between alumina surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kimiyasu, E-mail: sato.kimiyasu@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Y Latin-Small-Letter-Dotless-I lmaz, Hueseyin [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Gebze Institute of Technology, Materials Science and Engineering Department, 41400, Gebze-Kocaeli (Turkey); Ijuin, Atsuko; Hotta, Yuji; Watari, Koji [National Institute of Advanced Industrial Science and Technology (AIST), Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan)

    2012-02-01

    Low-molecular-weight organic acids have been known to modify colloidal stability of alumina-based suspensions. We investigated interaction forces between alumina surfaces mediated by acetic acid which is one of the simplest organic acids. Forces between alumina surfaces were measured using the colloid-probe method of atomic force microscope (AFM). Repulsive forces attributed to steric repulsion due to adsorbed molecules and electrostatic repulsion dominated the interaction. Results of rheological characterization of the alumina slurry containing acetic acid supported the finding.

  9. Topical use of tea tree oil reduces the dermal absorption of benzoic acid and methiocarb.

    Science.gov (United States)

    Nielsen, Jesper Bo; Nielsen, Flemming

    2006-03-01

    Tea tree oil (TTO) is a complex mixture of terpene hydrocarbons. Intensive topical use of TTO in different cosmetics and investigations into its potential as an antimicrobial or anti-inflammatory agent has accentuated the need for studies on the toxicity of TTO. We have applied an experimental in vitro model using static diffusion cells with human skin to study penetration characteristics of terpinen-4-ol and the way TTO affects the barrier integrity of the skin and the percutaneous penetration of two chemicals covering a range of solubilities from 0.03 g/l (methiocarb) to 3.0 g/l (benzoic acid). Through GC-MS analysis we identified the major constituents of TTO. In our experimental set-up with full-thickness skin, only the least lipophilic ingredients of TTO penetrated the skin. Barrier integrity was evaluated through measurement of percutaneous penetration of tritiated water. Data indicate that 1% TTO does not affect barrier conditions. The Kp value for tritiated water was increased significantly at 5% TTO, which demonstrate that the barrier integrity is affected at this relatively low concentration of TTO. The barrier integrity is, however, not seriously damaged, but our data indicate an initiated and concentration-dependent effect on the barrier integrity. TTO changed the penetration characteristics for benzoic acid as well as for methiocarb. The general effect was that TTO reduced the maximal flux. For methiocarb, the lag-time was also prolonged by increasing the TTO concentration in the donor phase to 5%. Thus, TTO reduced the overall amount of benzoic acid as well as methiocarb entering the receptor chamber.

  10. Dietary exposure of secondary school students in Hong Kong to benzoic acid in prepackaged non-alcoholic beverages.

    Science.gov (United States)

    Ma, Ka Ming; Chan, Cheok Man; Chung, Stephen Wai Cheung; Ho, Yuk Yin; Xiao, Ying

    2009-01-01

    This study evaluated the dietary exposure of secondary school students in Hong Kong to benzoic acid from pre-packaged non-alcoholic beverages. Exposure was estimated using local food consumption data of secondary school students obtained by a semi-quantitative food frequency questionnaire in 2000 and the benzoic acid level detected in pre-packaged beverages, including soft drink (both diet/light and regular types), fruit juice, soy milk, Chinese tea and coffee/tea) available locally in late 2006. The estimated dietary exposure to benzoic acid from pre-packaged beverages of average and high consumers (95(th) percentile) was 0.31 and 0.97 mg kg(-1) bw day(-1), respectively. These exposures accounted for 6.1 and 19.3% of the acceptable daily intake (ADI: 0-5 mg kg(-1) bw) of benzoic acid for average and high consumers, respectively. As in other countries, soft drinks contributed most to dietary exposure to benzoic acid from pre-packaged beverages in Hong Kong.

  11. A benzoic acid derivative and flavokawains from Piper species as schistosomiasis vector controls.

    Science.gov (United States)

    Rapado, Ludmila N; Freitas, Giovana C; Polpo, Adriano; Rojas-Cardozo, Maritza; Rincón, Javier V; Scotti, Marcus T; Kato, Massuo J; Nakano, Eliana; Yamaguchi, Lydia F

    2014-04-23

    The search of alternative compounds to control tropical diseases such as schistosomiasis has pointed to secondary metabolites derived from natural sources. Piper species are candidates in strategies to control the transmission of schistosomiasis due to their production of molluscicidal compounds. A new benzoic acid derivative and three flavokawains from Piper diospyrifolium, P. cumanense and P. gaudichaudianum displayed significant activities against Biomphalaria glabrata snails. Additionally, "in silico" studies were performed using docking assays and Molecular Interaction Fields to evaluate the physical-chemical differences among the compounds in order to characterize the observed activities of the test compounds against Biomphalaria glabrata snails.

  12. ADSORPTION OF BENZOIC ACID AND P-NITROBENZOIC ACID ON A NEW HYPERCROSSLINKED PHENOL GROUP PST ADSORBENT

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gencheng; LIUFuqiang; FEI Zhenghao; LI Aimin; ZHANG Quanxing

    2003-01-01

    A comparison of the adsorption of benzoic acid and p-nitrobenzoic acid on the new hypercrosslinked polymeric adsorbent AM-I, with that by macroporous Amberlite XAD-4, including the equilibrium adsorption isotherms, the dynamic adsorption behaviors through column and the adsorption thermodynamics were studied. Results show that Freundlich equation gives a fitting adsorption isotherm. The specific surface of AM-l is only 67% of that of Amberlite XAD-4, but the adsorption capacities on AM-1 are much higher about 125%~166% than that on Amberlite XAD-4,which is contributed to the micropore mechanism and polarity. The negative values of the adsorption enthalpy are indicative of an exothermic process. Enthalpy and free energy changes of adsorption both manifest a physic-sorption process. The negative values of the adsorption entropy indicate that the adsorption is well consistent with the restricted mobilities and the configurations of the adsorbed benzoic acid molecules on the surface of studied adsorbents with superficial heterogeneity. Both adsorbents were used in mini-column experiments for adsorbing benzoic acid expecting to elucidate the higher breakthrough adsorption capacity of the new hypercrosslinked polymeric adsorbent AM-1 as compared with that of Amberlite XAD-4.

  13. Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

    Science.gov (United States)

    Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

    2015-05-01

    In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid.

  14. Emissions of sulfur-containing odorants, ammonia, and methane from pig slurry: effects of dietary methionine and benzoic acid.

    Science.gov (United States)

    Eriksen, Jørgen; Adamsen, Anders Peter S; Nørgaard, Jan V; Poulsen, Hanne D; Jensen, Bent Borg; Petersen, Søren O

    2010-01-01

    Supplementation of benzoic acid to pig diets reduces the pH of urine and may thereby affect emissions of ammonia and other gases from slurry, including sulfur-containing compounds that are expected to play a role in odor emission. Over a period of 112 d, we investigated hydrogen sulfide (H(2)S), methanethiol (MT), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), and dimethyl trisulfide (DMTS), as well as ammonia and methane emissions from stored pig slurry. The slurry was derived from a feeding experiment with four pig diets in a factorial design with 2% (w/w) benzoic acid and 1% (w/w) methionine supplementation as treatments. Benzoic acid reduced slurry pH by 1 to 1.5 units and ammonia emissions by 60 to 70% for up to 2 mo of storage, and a considerable, but transitory reduction of methane emissions was also observed after 4 to 5 wk. All five volatile sulfur (S) compounds were identified in gas emitted from the slurry of the control treatment, which came from pigs fed according to Danish recommendations for amino acids and minerals. The emission patterns of volatile S compounds suggested an intense cycling between pools of organic S in the slurries, with urinary sulfate as the main source. Diet supplementation with methionine significantly increased all S emissions. Diet supplementation with benzoic acid reduced emissions of H(2)S and DMTS compared with the control slurry and moderately increased the concentrations of MT. Sulfur gas emissions were influenced by a strong interaction between methionine and benzoic acid treatments, which caused a significant increase in emissions of especially MT, but also of DMDS. In conclusion, addition of 2% benzoic acid to pig diets effectively reduced ammonia volatilization, but interactions with dietary S may increase odor problems.

  15. Effects of benzoic acid on nitrogen, phosphorus and energy balance and on ammonia emission from slurries in the heavy pig

    Directory of Open Access Journals (Sweden)

    G. Matteo Crovetto

    2011-07-01

    Full Text Available The effects of two dietary levels of benzoic acid on nitrogen, phosphorus and energy balance were evaluated in the typical Italian heavy pig during the last phase of growth. Six Landrace x Large White barrows of 125 kg body weight (BW on average were used in a repeated 3x3 Latin Square design and housed in metabolic cages to collect faeces and urine separately, in 3 collection periods of 7 days, after 14 days of adaptation. The animals were individually housed in open circuit respiration chambers to determine the energy metabolism. The dietary treatments were as follows [% on dry matter (DM]: i diet C (control: 14.2 crude protein (CP, 3.7 EE, 13.8 NDF; ii diet B05: diet C plus 0.5% benzoic acid; iii diet B10: diet C plus 1.0% benzoic acid. DM fed was fixed at 6.8% BW0.75. Apparent digestibility was similar among treatments for all the parameters studied. Nitrogen (N retention was 35.8, 37.4, 41.6% of intake N for C, B05 and B10, respectively, with no significant difference. Energy and phosphorus balances were not influenced by dietary treatments. Ammonia nitrogen emission from the slurry, expressed as a proportion of the initial slurry nitrogen, was decreased (P=0.049 by the inclusion of benzoic acid in the diet: 35.2, 28.1, 26.2% for C, B05, B10, respectively. The addition of benzoic acid to the diet determined a numerically decrease of the urinary pH. In conclusion, the inclusion of benzoic acid in the diet of the heavy pig is beneficial to the environment without effects on N, phosphorus (P and energy balances.

  16. The mechanism and kinetics of the electrochemical cleavage of azo bond of 2-hydroxy-5-sulfophenyl-azo-benzoic acids

    Energy Technology Data Exchange (ETDEWEB)

    Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

    2004-02-15

    The electrochemical reduction of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(3-sulfophenyl)azo]benzoic acid, 2-hydroxy-5-[(2-sulfophenyl)azo]benzoic acid and 2-hydroxy-5-azo-benzoic acid has been carried out in aqueous solutions at glassy carbon electrode using cyclic voltammetry and chronoamperometry. The position of sulfo substituent relative to azo bridge as well as pH of the solution have significant impact on the electrochemical behavior of these compounds. It has been proposed that these compounds are reduced predominantly as hydrazone tautomers resulting in corresponding hydrazo compounds. The overall electrochemical reduction follows DISP2 mechanism, ultimately leading to the 5-amino salicylic acid and sulfanilic acid. The rate determining step is the homogenous redox reaction between intermediate hydrazo compound and 5-amino salicylic acid quinoneimine. The mechanism is proposed in which activated complex of 5-amino salicylic acid quinoneimine and intermediate hydrazo compound is formed with the simultaneous loss of one proton.

  17. The benzoic acid-water complex: a potential atmospheric nucleation precursor studied using microwave spectroscopy and ab initio calculations.

    Science.gov (United States)

    Schnitzler, Elijah G; Jäger, Wolfgang

    2014-02-14

    The pure rotational, high-resolution spectrum of the benzoic acid-water complex was measured in the range of 4-14 GHz, using a cavity-based molecular beam Fourier-transform microwave spectrometer. In all, 40 a-type transitions and 2 b-type transitions were measured for benzoic acid-water, and 12 a-type transitions were measured for benzoic acid-D2O. The equilibrium geometry of benzoic acid-water was determined with ab initio calculations, at the B3LYP, M06-2X, and MP2 levels of theory, with the 6-311++G(2df,2pd) basis set. The experimental rotational spectrum is most consistent with the B3LYP-predicted geometry. Narrow splittings were observed in the b-type transitions, and possible tunnelling motions were investigated using the B3LYP/6-311++G(d,p) level of theory. Rotation of the water moiety about the lone electron pair hydrogen-bonded to benzoic acid, across a barrier of 7.0 kJ mol(-1), is the most likely cause for the splitting. Wagging of the unbound hydrogen atom of water is barrier-less, and this large amplitude motion results in the absence of c-type transitions. The interaction and spectroscopic dissociation energies calculated using B3LYP and MP2 are in good agreement, but those calculated using M06-2X indicate excess stabilization, possibly due to dispersive interactions being over-estimated. The equilibrium constant of hydration was calculated by statistical thermodynamics, using ab initio results and the experimental rotational constants. This allowed us to estimate the changes in percentage of hydrated benzoic acid with variations in the altitude, region, and season. Using monitoring data from Calgary, Alberta, and the MP2-predicted dissociation energy, a yearly average of 1% of benzoic acid is expected to be present in the form of benzoic acid-water. However, this percentage depends sensitively on the dissociation energy. For example, when using the M06-2X-predicted dissociation energy, we find it increases to 18%.

  18. Using a Simulated Industrial Setting for the Development of an Improved Solvent System for the Recrystallization of Benzoic Acid: A Student-Centered Project

    Science.gov (United States)

    Hightower, Timothy R.; Heeren, Jay D.

    2006-01-01

    Recrystallization of benzoic acid is an excellent way to remove insoluble impurities. In a traditional organic laboratory experiment, insoluble impurities are removed through the recrystallization of benzoic acid utilizing water as the recrystallization solvent. It was our goal to develop a peer-led, problem-solving organic laboratory exercise…

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  20. Hydrogen production by fermentation using acetic acid and lactic acid.

    Science.gov (United States)

    Matsumoto, Mitsufumi; Nishimura, Yasuhiko

    2007-03-01

    Microbial hydrogen production from sho-chu post-distillation slurry solution (slurry solution) containing large amounts of organic acids was investigated. The highest hydrogen producer, Clostridium diolis JPCC H-3, was isolated from natural environment and produced hydrogen at 6.03+/-0.15 ml from 5 ml slurry solution in 30 h. Interestingly, the concentration of acetic acid and lactic acid in the slurry solution decreased during hydrogen production. The substrates for hydrogen production by C. diolis JPCC H-3, in particular organic acids, were investigated in an artificial medium. No hydrogen was produced from acetic acid, propionic acid, succinic acid, or citric acid on their own. Hydrogen and butyric acid were produced from a mixture of acetic acid and lactic acid, showing that C. diolis. JPCC H-3 could produce hydrogen from acetic acid and lactic acid. Furthermore, calculation of the Gibbs free energy strongly suggests that this reaction would proceed. In this paper, we describe for the first time microbial hydrogen production from acetic acid and lactic acid by fermentation.

  1. Sorbic and benzoic acid in non-preservative-added food products in Turkey.

    Science.gov (United States)

    Cakir, Ruziye; Cagri-Mehmetoglu, Arzu

    2013-01-01

    Sorbic acid (SA) and benzoic acid (BA) were determined in yoghurt, tomato and pepper paste, fruit juices, chocolates, soups and chips in Turkey by using high-pressure liquid chromatography (HPLC). Levels were compared with Turkish Food Codex limits. SA was detected only in 2 of 21 yoghurt samples, contrary to BA, which was found in all yoghurt samples but one, ranging from 10.5 to 159.9 mg/kg. Both SA and BA were detected also in 3 and 6 of 23 paste samples in a range of 18.1-526.4 and 21.7-1933.5 mg/kg, respectively. Only 1 of 23 fruit juices contained BA. SA was not detected in any chips, fruit juice, soup, or chocolate sample. Although 16.51% of the samples was not compliant with the Turkish Food Codex limits, estimated daily intake of BA or SA was below the acceptable daily intake.

  2. 3,5-Bis[(pyridin-4-ylmethoxy]benzoic acid

    Directory of Open Access Journals (Sweden)

    Hong Lin

    2013-01-01

    Full Text Available Single crystals of the title compound, C19H16N2O4, were obtained under hydrothermal conditions by an unintended recrystallization of the employed microcrystalline starting material. The [(pyridin-4-ylmethoxy]benzoic acid unit is nearly planar, with a maximum deviation from the least-squares plane of 0.194 (2 Å. This plane is inclined by 35.82 (6° to that defined by the second (pyridin-4-ylmethoxy group [in which the largest deviation from the least-squares plane is 0.013 (2 Å]. In the crystal, molecules are linked by O—H...N hydrogen bonds involving the acid hydroxy group and a pyridine N atom into chains parallel to [-201].

  3. Preparation and Physical Properties of Chitosan Benzoic Acid Derivatives Using a Phosphoryl Mixed Anhydride System

    Directory of Open Access Journals (Sweden)

    Kyu Yun Chai

    2012-02-01

    Full Text Available Direct benzoylation of the two hydroxyl groups on chitosan was achieved using a phosphoryl mixed anhydride system, derived from trifluoroacetic anhydride (TFAA, benzoic acids (BAs, and phosphoric acid (PA. The reaction is operated as a one pot process under mild conditions that does not require neither an inert atmosphere nor dry solvents. The structures of the synthesized compounds were confirmed by NMR and IR spectroscopy. Solubility tests on the products revealed that they were soluble in organic solvents such as N,N-dimethylformamide (DMF, dimethylsulfoxide (DMSO, and acetone. In the meantime, a morphological study by scanning electron microscopy (SEM evidently indicated that the chitosan benzoates underwent significant structural changes after the benzoylation.

  4. Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

    Science.gov (United States)

    Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng

    2014-03-01

    MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H2O2 indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions.

  5. Syntheses,characteristics and fluorescence properties of complexes of terbium with benzoic acid and its derivatives

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhong-cheng; SHU Wan-gen; RUAN Jian-ming; HUANG Bai-yun; LIU You-nian

    2005-01-01

    The binary complexes of terbium with benzoic acid and its derivatives (phthalic acid,iso-phthalic acid,oaminobenzoic acid,salicylic acid,sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses.UV,IR of the complexes were investigated.The UV spectra indicate that the complexes'ultraviolet absorption is mainly the ligands' absorption,but the location of peak drifts.The IR spectra show that the IR spectra of complexes are different from those of free ligands,and the band at 400-500 cm-1,due to the stretching vibration of Tb-O,is absent for free ligands.The fluorescence properties were investigated by using luminescence spectroscope,the results show that all the six complexes of terbium exhibit excellent luminescence,due to the transition from the lowest excited state 5D4 to 7F ground state manifold,the complexes of terbium with sulfosalicylic acid have the strongest fluorescence intensity,and is stronger than o-aminobenzoic acid-terbium,whose fluorescence intensity is regarded as the strongest one in the literature,and even stronger than some phosphor of terbium.

  6. One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

    Directory of Open Access Journals (Sweden)

    Mohammad Abbasi

    2015-07-01

    Full Text Available An efficient and odourless procedure for a one-pot synthesis of thioesters by the reaction of benzoic anhydrides, thiourea and various organic halides (primary, allylic, and benzylic or structurally diverse, electron-deficient alkenes (ketones, esters, and nitriles in the presence of Et3N has been developed. In this method, thiobenzoic acids were in situ generated from the reaction of thiourea with benzoic anhydrides, which were subjected to conjugate addition with electron-deficient alkenes or a nucleophilic displacement reaction with alkyl halides.

  7. 40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

    Science.gov (United States)

    2010-07-01

    ... amino-, di-2-propenyl ester. 721.1725 Section 721.1725 Protection of Environment ENVIRONMENTAL...-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i)...

  8. Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  9. Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  10. Comparison of inhibition effects of some benzoic acid derivatives on sheep heart carbonic anhydrase

    Science.gov (United States)

    Kiliç, Deryanur; Yildiz, Melike; Şentürk, Murat; Erdoǧan, Orhan; Küfrevioǧlu, Ömer Irfan

    2016-04-01

    Carbonic anhydrase (CA) is a family of metalloenzymes that requires Zn as a cofactor and catalyze the quick conversion of CO2 to HCO3- and H+. Inhibitors of the carbonic anhydrases (CAs) have medical usage of significant diseases such as glaucoma, epilepsy, gastroduodenal ulcers, acid-base disequilibria and neurological disorders. In the present study, inhibition of CA with some benzoic derivatives (1-6) were investigated. Sheep heart CA (shCA) enzyme was isolated by means of designed affinity chromatography gel (cellulose-benzyl-sulfanylamide) 42.45-fold in a yield of 44 % with 564.65 EU/mg. Purified shCA enzyme was used in vitro studies. In the studies, IC50 values were calculated for 3-aminobenzoic acid (1), 4-aminobenzoic acid (2), 2-hydroxybenzoic acid (3), 2-benzoylbenzoic acid (4), 2,3-dimethoxybenzoic acid (5), and 3,4,5-trimethoxybenzoic acid (6), showing the inhibition effects on the purified enzyme. Such molecules can be used as pioneer for discovery of novel effective CA inhibitors for medicinal chemistry applications.

  11. Complexation of uranium(VI) with aromatic acids in aqueous solution. A comparison of hydroxamic acids and benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Glorius, M.; Moll, H.; Bernhard, G. [Forschungszentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. fuer Radiochemie

    2007-07-01

    The complex formation of uranium(VI) with salicylhydroxamic,benzohydroxamic, and benzoic acid in 0.1 M NaClO{sub 4} was studied by UV-vis spectroscopy at pH 3 and 4. Uranium(VI) species of the type M{sub p}L{sub q}H{sub r} were identified from the UV-vis spectra in all three systems. An increase in the absorption combined with a blue shift of the absorption maxima in comparison to the bands of the free uranyl ion of 22.5 {+-} 2 nm was observed in the uranium (VI)-salicylhydroxamic acid-system. Besides indications for a 1:2 complex, the formation of a 1:1 complex with a stability constant of log {beta}{sub 111} = 17.12 {+-} 0.10 could be demonstrated by its individual absorption spectrum and molar absorption coefficient. Also in the uranium(VI)-benzohydroxamic acid-system a blue shift of the absorption maxima in comparison to the bands of the free uranyl ion of 27 {+-} 1.4 nm indicate the complex formation. The stability constants are log {beta}{sub 110} = 7.96 {+-} 0.05 for UO{sub 2}[C{sub 6}H{sub 4}CONHO]{sup +} and log {beta}{sub 120} = 15.25 {+-} 0.11 for UO{sub 2}[C{sub 6}H{sub 4}CONHO]{sub 2}. In contrast to the hydroxamic acids, benzoic acid shows a red shift of the absorption maxima of 2.5 {+-} 2 nm. Only the 1:1 complex UO{sub 2}[C{sub 6}H{sub 4}COO]{sup +} with a stability constant of log {beta}{sub 110} = 3.37 {+-} 0.14 is existent. An estimate is made in order to discuss the dependencies observed in the absorption spectra in relation to possible coordination modes of uranium(VI). The strength of the complex formation between uranyl and the three aromatic acids is discussed. (orig.)

  12. Determination of combined p-hydroxy benzoic acid preservatives in a liquid pharmaceutical formulation by HPLC.

    Science.gov (United States)

    Shabir, Ghulam A

    2004-01-27

    This paper describes a reversed-phase high performance liquid chromatographic (RP-HPLC) assay method for the determination of combined p-hydroxy benzoic acid (ethylparaben (EP), methylparaben (MP) and propylparaben (PP)) preservatives in a liquid pharmaceutical formulation. The chromatographic separation was achieved with potassium phosphate buffer (pH 7.05)-methanol (47.5:52.5, v/v) as mobile phase, a Spherisorb C(18) column (250 mm x 4.6mm) and UV detection at 254 nm. The analysis time was 0.9999 in each case. The relative standard deviation (R.S.D.) values for intra- and inter-day precision studies were <1%. The procedure describe here is simple, selective and is suitable for routine quality control analysis and stability tests.

  13. Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S. D.

    1998-12-01

    Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

  14. Probe depth matters in dermal microdialysis sampling of benzoic acid after topical application

    DEFF Research Database (Denmark)

    Holmgaard, R; Benfeldt, E; Bangsgaard, N

    2012-01-01

    Microdialysis (MD) in the skin - dermal microdialysis (DMD) - is a unique technique for sampling of topically as well as systemically administered drugs at the site of action, e.g. sampling of dermatological drug concentrations in the dermis. Debate has concerned the existence of a correlation...... between the depth of the sampling device - the probe - in the dermis and the amount of drug sampled following topical drug administration. This study evaluates the relation between probe depth and drug sampling using dermal DMD sampling ex vivo in human skin. We used superficial (...-2 mm) and deep (>2 mm) positioning of the linear MD probe in the dermis of human abdominal skin, followed by topical application of 4 mg/ml of benzoic acid (BA) in skin chambers overlying the probes. Dialysate was sampled every hour for 12 h and analysed for BA content by high-performance liquid...

  15. Temperature-dependent benzoic acid elimination mechanisms in pyrolysis of (--cocaine

    Directory of Open Access Journals (Sweden)

    Michal Novák

    2011-01-01

    Full Text Available The thermal elimination of benzoic acid from (--cocaine is shown to be temperature-dependent. In the temperature range of 200-500 °C only a trans-elimination is observed leading to methylecgonidine. Above ca. 500 °C a second mechanism, the cis-elimination, comes up yielding a novel alkaloid methylisoecgonidine which has been characterized by means of mass spectrometry. At 600 °C the cis-elimination predominates. The trans-elimination is postulated a two-step process consisting of a 1,7- and a 1,5-hydrogen shift. The chemistry of cocaine base smoking is explained using the theory of chemical activation.

  16. Synthesis and Crystal Structure of a Complex of Melamine with Benzoic Acid

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiu-lian

    2008-01-01

    A new complex of melamine(MA) with benzoic acid(HBA) was prepared,affording [(HMA+)(BA-)]·2H2O.Each HBA molecule is deprotonated and one triazine nitrogen atom of MA is protonated,The adjacent HMA+ cations are hydrogen bonded to alternate sides of the (HMA+)∞ ribbons to generate indention 1D tapes,which are extended into the hydrogen bond present in the complex are anion/water and amino/water tape structures,The hydrogen-bonding patterns consist of alternate 6,10-membered rings sharing two edges,Infrared(IR) spectroscopy conforms that proton transfer has taken place in the complex.

  17. Iron-catalyzed photochemical transformation of benzoic acid in atmospheric liquids: Product identification and reaction mechanisms

    Science.gov (United States)

    Deng, Yiwei; Zhang, Kai; Chen, Hao; Wu, Taixing; Krzyaniak, Metthew; Wellons, Amina; Bolla, Dawn; Douglas, Kenneth; Zuo, Yuegang

    This study investigated iron-catalyzed photochemical oxidation of benzoic acid (BA), one of the major photodegradation products of petroleum hydrocarbons, under sunlight or monochromatic light irradiation in a wavelength range of 254-419 nm. The photochemical degradation of BA in the absence of iron (III) occurred at irradiation wavelengths below 300 nm. The photochemical transformation of BA in the presence Fe(III) was observed at both 254, 350, 419 nm and under solar irradiation. The half-life for the photodegradation of BA (100 μM) was 160±20 min in the presence of 20 μM Fe(III) at pH 3.20 on sunny August days at noon time. The degradation rate increased with increasing concentration of Fe(III). The reaction products were separated and identified using capillary electrophoresis (CE), gas chromatography/mass spectrometry (GC/MS) and UV-Visible spectrophotometry. The major reaction products were 2-hydroxybenzoic, 3-hydroxybenzoic and 4-hydroxybenzoic acids. Hydrogen peroxide (H 2O 2) and Fe(II) species were also formed during the photochemical reactions. The proposed reaction mechanisms include the photoexcitation of Fe(III) hydroxide complexes to form Fe(II) ions and hydroxyl radicals (OH rad ) that attack ortho, meta and para positions of BA to form corresponding monohydroxybenzoic acids and H 2O 2. The monohydroxybenzoic acids formed further react with hydroxyl and surperoxide radicals (HO 2- rad /O 2- rad ) to yield dihydroxybenzoic acids in atmospheric water droplets.

  18. Synthesis, oxygenation and catalytic performance of manganese complex with p-aminomethyl benzoic acid Schiff base

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy,dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-keto-dehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60℃C, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.

  19. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  20. Kinetics of wet oxidation of formic acid and acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. [Univ. of Mumbai (India). Dept. of Chemical Technology

    1997-11-01

    Oxidation of lower molecular weight carboxylic acids such as formic, acetic, glyoxalic, and oxalic acids is often the rate-controlling step during wet oxidation (WO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WO of formic acid was studied in the absence and presence of a cupric sulfate as catalyst in the temperature range 150--240 C and oxygen partial pressure range 0.345--1.380 MPa. Wet oxidation of acetic acid was carried out in the presence of cupric sulfate in the temperature range 215--235 C. Homogeneous copper sulfate was found to be a very good catalyst for oxidation of formic acid and acetic acid.

  1. On the Formation of Benzoic Acid and Higher Order Benzene Carboxylic Acids in Interstellar Model Ices grains

    Science.gov (United States)

    McMurtry, Brandon M.; Saito, Sean E. J.; Turner, Andrew M.; Chakravarty, Harish K.; Kaiser, Ralf I.

    2016-11-01

    With a binary ice mixture of benzene (C6H6) and carbon dioxide (CO2) at 10 K under contamination-free ultrahigh vacuum conditions, the formation of benzene carboxylic acids in interstellar ice grains was studied. Fourier transform infrared spectroscopy was used to probe for the formation of new species during the chemical processing of the ice mixture and during the following temperature-programmed desorption. Newly formed benzene carboxylic acid species, i.e., benzoic acid, as well as meta- and para-benzene dicarboxylic acid, were assigned using newly emerging bands in the infrared spectrum; a reaction mechanism, along with rate constants, was proposed utilizing the kinetic fitting of the coupled differential equations.

  2. Rotational study of the bimolecule acetic acid-fluoroacetic acid

    Science.gov (United States)

    Feng, Gang; Gou, Qian; Evangelisti, Luca; Caminati, Walther

    2017-01-01

    The rotational spectrum of the acetic acid-fluoroacetic acid bimolecule was measured by using a pulsed jet Fourier transform microwave spectrometer. One conformer, in which fluoroacetic acid is in trans form, has been observed. The rotational transitions are split into two component lines, due to the internal rotation of the methyl group of acetic acid. From these splittings, the corresponding V3 barrier has been determined. The dissociation energy of this complex has been estimated to 66 kJ/mol. An increase of the distance between the two monomers upon the OH → OD substitution (Ubbelohde effect) has been observed.

  3. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    Science.gov (United States)

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  4. Effect of temperature and concentration on benzoyl peroxide bleaching efficacy and benzoic acid levels in whey protein concentrate.

    Science.gov (United States)

    Smith, T J; Gerard, P D; Drake, M A

    2015-11-01

    Much of the fluid whey produced in the United States is a by-product of Cheddar cheese manufacture and must be bleached. Benzoyl peroxide (BP) is currently 1 of only 2 legal chemical bleaching agents for fluid whey in the United States, but benzoic acid is an unavoidable by-product of BP bleaching. Benzoyl peroxide is typically a powder, but new liquid BP dispersions are available. A greater understanding of the bleaching characteristics of BP is necessary. The objective of the study was to compare norbixin destruction, residual benzoic acid, and flavor differences between liquid whey and 80% whey protein concentrates (WPC80) bleached at different temperatures with 2 different benzoyl peroxides (soluble and insoluble). Two experiments were conducted in this study. For experiment 1, 3 factors (temperature, bleach type, bleach concentration) were evaluated for norbixin destruction using a response surface model-central composite design in liquid whey. For experiment 2, norbixin concentration, residual benzoic acid, and flavor differences were explored in WPC80 from whey bleached by the 2 commercially available BP (soluble and insoluble) at 5 mg/kg. In liquid whey, soluble BP bleached more norbixin than insoluble BP, especially at lower concentrations (5 and 10 mg/kg) at both cold (4°C) and hot (50°C) temperatures. The WPC80 from liquid whey bleached with BP at 50°C had lower norbixin concentration, benzoic acid levels, cardboard flavor, and aldehyde levels than WPC80 from liquid whey bleached with BP at 4°C. Regardless of temperature, soluble BP destroyed more norbixin at lower concentrations than insoluble BP. The WPC80 from soluble-BP-bleached wheys had lower cardboard flavor and lower aldehyde levels than WPC80 from insoluble-BP-bleached whey. This study suggests that new, soluble (liquid) BP can be used at lower concentrations than insoluble BP to achieve equivalent bleaching and that less residual benzoic acid remains in WPC80 powder from liquid whey

  5. Adaptation and tolerance of bacteria against acetic acid.

    Science.gov (United States)

    Trček, Janja; Mira, Nuno Pereira; Jarboe, Laura R

    2015-08-01

    Acetic acid is a weak organic acid exerting a toxic effect to most microorganisms at concentrations as low as 0.5 wt%. This toxic effect results mostly from acetic acid dissociation inside microbial cells, causing a decrease of intracellular pH and metabolic disturbance by the anion, among other deleterious effects. These microbial inhibition mechanisms enable acetic acid to be used as a preservative, although its usefulness is limited by the emergence of highly tolerant spoilage strains. Several biotechnological processes are also inhibited by the accumulation of acetic acid in the growth medium including production of bioethanol from lignocellulosics, wine making, and microbe-based production of acetic acid itself. To design better preservation strategies based on acetic acid and to improve the robustness of industrial biotechnological processes limited by this acid's toxicity, it is essential to deepen the understanding of the underlying toxicity mechanisms. In this sense, adaptive responses that improve tolerance to acetic acid have been well studied in Escherichia coli and Saccharomyces cerevisiae. Strains highly tolerant to acetic acid, either isolated from natural environments or specifically engineered for this effect, represent a unique reservoir of information that could increase our understanding of acetic acid tolerance and contribute to the design of additional tolerance mechanisms. In this article, the mechanisms underlying the acetic acid tolerance exhibited by several bacterial strains are reviewed, with emphasis on the knowledge gathered in acetic acid bacteria and E. coli. A comparison of how these bacterial adaptive responses to acetic acid stress fit to those described in the yeast Saccharomyces cerevisiae is also performed. A systematic comparison of the similarities and dissimilarities of the ways by which different microbial systems surpass the deleterious effects of acetic acid toxicity has not been performed so far, although such exchange

  6. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    Science.gov (United States)

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress.

  7. Determination of the limit of quantification of the calorimeter using a mixture of benzoic acid and silicon dioxide

    Directory of Open Access Journals (Sweden)

    Krstić Vesna R.

    2011-01-01

    Full Text Available In recent years quality control has received a great attention in laboratory work. Implementation of the international standard ISO/IEC 17025 is necessary for any laboratory that wishes to establish quality control in its work. One of the important factors for meeting the requirements of this standard is the usage of the certified reference materials (CRM in laboratory work. In order to determine the performance of the calorimeter, benzoic acid as CRM, from AlliedSignal Riedelda Haen, Ref.: 33045 and SiO2, Pro analyze, in various mass ratios was used. The results showed that benzoic acid can be successfully utilized for the control of the entire technical and instrumental measuring range and resolve the problem of determination of the limit of detection and quantification of the calorimeter.

  8. Natural oils affect the human skin integrity and the percutaneous penetration of benzoic acid dose-dependently

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo

    2006-01-01

    Abstract: Natural oils are extensively used in cosmetics and as treatment for a growing number of more or less specific ailments. Skin irritation and cases of allergy have repeatedly been described in the literature following exposure to these oils. The present study evaluated the extent to which...... three natural oils (eucalyptus oil, tea tree oil, peppermint oil) would affect the skin integrity and the percutaneous penetration of benzoic acid when applied topically in relevant concentrations. An experimental in vitro model using static diffusion cells mounted with human breast or abdominal skin...... was applied. The three natural oils decreased the skin integrity dose-dependently. Concomitant dermal exposure to low concentrations of peppermint oil reduced the percutaneous penetration of benzoic acid. The present study lends support to the notion that low concentrations of peppermint oil may act...

  9. Self-assembled structure of alkyloxy substituted benzoic acid methyl ester on HOPG:An STM study

    Institute of Scientific and Technical Information of China (English)

    YUAN Qunhui; LU Jun; WAN Lijun; BAI Chunli

    2004-01-01

    Self-assembled structures of 3,4,5-tris-dodecy- loxy benzoic acid methyl ester (E12), 3,4,5-tris-tetradecy- loxy-benzoic acid methyl ester (E14) and their mixture (E12/E14) have been studied on HOPG by scanning tunneling microscopy (STM). Dimer-like patterns induced by dipole-dipole interaction are observed in E12 and E14 monolayers. The molecules form close-packed rows and interdigitate with the alkyl chains in adjacent molecules. The structural differences are proposed to be from the different length of substituted alkyl chains. Owing to similar adsorption energy, phase separation is observed in the E12 and E14 mixed adlayer with different domains.

  10. Modification of Poly Ethylene Glycol with 4, 4-Azo Di Benzoic Acid and Study of Its Physical Properties

    Directory of Open Access Journals (Sweden)

    *Z. A. AL Mousway

    2015-12-01

    Full Text Available Polyethylene glycol 20000 was modified by copolymerization with 4, 4-Azo di benzoic acid, using cold-warm esterfication. The modified copolymer has been characterized by Fourier transform infrared spectrophotometer (FT-IR which showed characteristic vibrational bands of OH, CO and N=N groups. The modified copolymer was subjected to differential scanning colorimeter (DSC, conductivity and swelling measurements. The obtained results of the thermal behavior (DSC for the different percentage of prepared copolymers were (I=10% PEG +10% 4, 4-Azo di benzoic acid= 54.2◦C, as well as (II=20% = 68.6◦C, (III=30% = 81.5◦C, (IV=40% = 93.3◦C and (V=50% = 120◦C. This means that perfect results when the polyethylene glycol 50% mixed with 50% of 4, 4-Azo di benzoic acid. While the conductivity of all copolymer in an aqueous phase with varying chain lengths of PEG reacted with 4, 4-Azo di benzoic acid, in different percentage were (I = 75.6, (II = 151.8, (III = 165.3, (IV = 226 and (V = 277 Λm(S.cm2.mol-1. In ethanol, the copolymers were observed to have electrolyte behaviors. The solubility of the prepared copolymer was tested in different solvents at 25◦C. It is highly soluble in DMSO and DMF and insoluble in other solvents. The experiment of measuring the degree of swelling under room temperature, in equal periods of time, showed good water uptake and required ~ 12 hours for reaching the equilibrium for the different percentage of prepared copolymers.

  11. PROPERTIES AND THERMODYNAMICS OF ADSORPTION OF BENZOIC ACID ONTO XAD-4 AND A WATER-COMPATIBLE HYPERCROSSLINKED ADSORBENT

    Institute of Scientific and Technical Information of China (English)

    Fu-qiang Liu; Jin-long Chen; Ai-min Li; Zheng-hao Fei; Zhao-lian Zhu; Quan-xing Zhang

    2003-01-01

    The adsorption behavior of benzoic acid onto a water-compatible hypercrosslinked polymeric adsorbent NJ-8 was compared with that onto macroporous Amberlite XAD-4. This paper focuses on the static equilibrium adsorption behaviors,the adsorption thermodynamics and the column dynamic adsorption profiles. Five isotherm models are used to fit the results.This shows that the Freundlich equation can give a perfect fit. The specific surface area of NJ-8 is about as high as that of Amberlite XAD-4, but the adsorbing capacity for benzoic acid on NJ-8 is about 14.9%-64.8% higher than that on Amberlite XAD-4, which is attributed to its microporous mechanism and partial polarity. The negative values of the adsorption enthalpy are indicative of an exothermic process. Both enthalpy and free energy changes of adsorption manifest a physical sorption process. The negative values of the adsorption entropy indicate that adsorption is well consistent with the restricted mobilities and the configurations of the adsorbed molecules on the surface of the studied adsorbents with superficial heterogeneity. Both adsorbents were used in mini-column experiments to demonstrate the higher breakthrough adsorbing capacity of the hypercrosslinked polymeric adsorbent NJ-8 to benzoic acid, as compared with that of Amberlite XAD-4.

  12. Spontaneous adsorption of 3,5-bis(3,5-dinitrobenzoylamino) benzoic acid onto carbon

    Energy Technology Data Exchange (ETDEWEB)

    Paez, Julieta I.; Strumia, Miriam C. [Departamento de Quimica Organica (IMBIV-CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba (5000) (Argentina); Passeggi, Mario C.G. [Laboratorio de Superficies e Interfaces (INTEC-CONICET), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santa Fe (3000) (Argentina); Ferron, Julio [Laboratorio de Superficies e Interfaces (INTEC-CONICET), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santa Fe (3000) (Argentina); Departamento de Materiales, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santa Fe (3000) (Argentina); Baruzzi, Ana M. [Departamento de Fisicoquimica (INFIQC-CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba (5000) (Argentina); Brunetti, Veronica [Departamento de Fisicoquimica (INFIQC-CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba (5000) (Argentina)], E-mail: brunetti@fcq.unc.edu.ar

    2009-07-01

    Dendritic molecules contain multifunctional groups that can be used to efficiently control the properties of an electrode surface. We are developing strategies to generate a highly functionalized surface using multifunctional and rigid dendrons immobilized onto different substrates. In the present work, we explore the immobilization of a dendritic molecule: 3,5-bis(3,5-dinitrobenzoylamino) benzoic acid (D-NO{sub 2}) onto carbon surfaces showing a simple and rapid way to produce conductive surfaces with electroactive chemical functions. The immobilized D-NO{sub 2} layer has been characterized using atomic force microscopy and cyclic voltammetry. D-NO{sub 2} adsorbs onto carbon surfaces spontaneously by dipping the electrode in dendron solutions. Reduction of this layer generates the hydroxylamine product. The resulting redox-active layer exhibits a well-behaved redox response for the adsorbed nitroso/hydroxylamine couple. The film permeability of the derivatized surface has been analyzed employing the electrochemical response of redox probes: Ru(NH{sub 3}){sub 6}{sup 3+}/Ru(NH{sub 3}){sub 6}{sup 2+} and Fe(CN){sub 6}{sup 3-}/Fe(CN){sub 6}{sup 4-}. Electrocatalytic oxidation of nicotinamide adenine dinucleotide onto a modified carbon surface was also observed.

  13. Short communication: Change of naturally occurring benzoic acid during skim milk fermentation by commercial cheese starters.

    Science.gov (United States)

    Han, Noori; Park, Sun-Young; Kim, Sun-Young; Yoo, Mi-Young; Paik, Hyun-Dong; Lim, Sang-Dong

    2016-11-01

    This study sought to investigate the change of naturally occurring benzoic acid (BA) during skim milk fermentation by 4 kinds of commercial cheese starters used in domestic cheese. The culture was incubated at 3-h intervals for 24h at 30, 35, and 40°C. The BA content during fermentation by Streptococcus thermophilus STB-01 was detected after 12h at all temperatures, sharply increasing at 30°C. In Lactobacillus paracasei LC431, BA was detected after 9h at all temperatures, sharply increasing until 18h and decreasing after 18h at 30 and 35°C. In the case of R707 (consisting of Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris), BA increased from 6h to 15h and decreased after 15h at 40°C. The BA during STB-01 and CHN-11 (1:1; mixture of S. thermophilus, Lc. lactis ssp. lactis, Lc. lactis ssp. cremoris, Lc. lactis ssp. diacetylactis, Leuconostoc mesenteroides ssp. cremoris) fermentation was detected after 3h at 35 and 40°C, sharply increasing up to 12h and decreasing after 15h at 35°C, and after 6h, increasing up to 9h at 30°C. After 3h, it steadily decreased at 40°C. The highest amount of BA was found during the fermentation by R707 at 30°C; 15h with 12.46mg/kg.

  14. Co-culture engineering for microbial biosynthesis of 3-amino-benzoic acid in Escherichia coli.

    Science.gov (United States)

    Zhang, Haoran; Stephanopoulos, Gregory

    2016-07-01

    3-amino-benzoic acid (3AB) is an important building block molecule for production of a wide range of important compounds such as natural products with various biological activities. In the present study, we established a microbial biosynthetic system for de novo 3AB production from the simple substrate glucose. First, the active 3AB biosynthetic pathway was reconstituted in the bacterium Escherichia coli, which resulted in the production of 1.5 mg/L 3AB. In an effort to improve the production, an E. coli-E. coli co-culture system was engineered to modularize the biosynthetic pathway between an upstream strain and an downstream strain. Specifically, the upstream biosynthetic module was contained in a fixed E. coli strain, whereas a series of E. coli strains were engineered to accommodate the downstream biosynthetic module and screened for optimal production performance. The best co-culture system was found to improve 3AB production by 15 fold, compared to the mono-culture approach. Further engineering of the co-culture system resulted in biosynthesis of 48 mg/L 3AB. Our results demonstrate co-culture engineering can be a powerful new approach in the broad field of metabolic engineering.

  15. Benzoic Acid Interactions Affect Aquatic Properties and Toxicity of Copper Oxide Nanoparticles.

    Science.gov (United States)

    Wang, Zhuang; Fang, Hao; Wang, Se

    2016-08-01

    Effects of benzoic acid (BA) on physicochemical properties and ecotoxicities of CuO nanoparticles (CuONPs) in model aqueous media were studied. The CuONPs had larger hydrodynamic sizes and higher surface zeta potentials during 96 h of settling in the presence of BA than when the BA were not present. BA interaction with CuONPs is shown to promote dissolved Cu release from CuONPs in a dose-dependent manner. The contribution of free Cu(2+)-ions to growth inhibition toxicity of the CuONP suspensions at a toxicologically relevant concentration for the green alga Scenedesmus obliquus was around 22 %, indicating that dissolved fraction was not the major source of toxicity of CuONPs. The toxicity of CuONPs increased as the BA concentration increased. BA significantly altered total antioxidant capacity of CuONPs-exposed algal cells. The mechanism of the BA effect on the CuONPs toxicity may be mainly associated with degree of agglomeration, dissolved Cu, and particle-induced oxidative stress.

  16. Metabolic engineering of Pseudomonas putida KT2440 for the production of para-hydroxy benzoic acid

    Directory of Open Access Journals (Sweden)

    Shiqin Yu

    2016-11-01

    Full Text Available para-hydroxy benzoic acid (PHBA is the key component for preparing parabens, a common preservatives in food, drugs and personal care products, as well as high performance bioplastics such as liquid crystal polymers (LCP. Pseudomonas putida KT2440 was engineered to produce PHBA from glucose via the shikimate pathway intermediate chorismate. To obtain the PHBA production strain, chorismate lyase UbiC from Escherichia coli and a feedback resistant 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase encoded by gene aroGD146N were overexpressed individually and simultaneously. In addition, genes related to product degradation (pobA or competing for the precursor chorismate (pheA and trpE were deleted from the genome. To further improve PHBA production, the glucose metabolism repressor hexR was knocked out in order to increase erythrose-4- phosphate and NAPH supply. The best strain achieved a maximum titre of 1.73 g L-1 and a carbon yield of 18.1 % (C-mol C-mol-1 in a non-optimized fed-batch fermentation. This is to date the highest PHBA concentration produced by P. putida using a chorismate lyase.

  17. Reactions of supercritical water with benzaldehyde, benzylidenebenzylamine, benzyl alcohol and benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, C.C.; Zhou, Y.; Liu, X.; Houser, T.J. (Western Michigan University, Kalamazoo, MI (USA). Dept. of Chemistry)

    1992-06-01

    This paper describes the results of reaction of benzaldehyde, benzyl alcohol, benzoic acid, and benzylidenebenzylamine with supercritical water (SW) since these compounds were determined or assumed to be major intermediates in the reaction of benzylamine with SW. Supplementary information was obtained from the benzyl benzoate-SW reaction. The kinetics of the benzaldehyde-SW reaction were found to be complex, second-order in benzaldehyde, and inhibited by product(s). The Arrhenius parameters for the second-order rate constant are an activation energy of 179 kJ mol[sup -1] and preexponential factor of 1.6 x 10 (10) M[sup -1]s[sup -1]. In addition, the influences of ammonia and dihydroanthracene on some of the product distributions and extents of reaction were determined. Of particular interest is the reaction pathway leading to the formation of benzene and related products which requires an oxidation/hydrolysis sequence, terminated by decarboxylation to form hydrocarbons. The mechanistic significance of the benzene/tpluene product-yield ratios is discussed.

  18. Polyoxometalate coordinated transition metal complexes as catalysts: Oxidation of styrene to benzaldehyde/benzoic acid

    Indian Academy of Sciences (India)

    Srinivasa Rao Amanchi; Anjali Patel; Samar K Das

    2014-11-01

    Oxidation of styrene is carried out by using heptamolybdate coordinated transition metal (Co2+, Zn2+) complexes, [2-ampH]4[{Co(H2O)5}Mo7O24]·9H2O (1), [3-ampH]4[{Co(H2O)5}Mo7O24]·9H2O (2), [2-ampH]4[{Zn(H2O)5}Mo7O24]·4H2O (3) and [3-ampH]4[{Zn(3-ampy)(H2O)4}Mo7O24]·4H2O (4) as catalysts and H2O2 as an oxidant at 80°C. The leaching study has been carried out to check the quality of catalyst and it has been reused for three times with good percentage of conversion. For the first two catalysts (compounds 1 and 2), the major product obtained is benzaldehyde, and benzoic acid is the major product for next two catalysts (compounds 3 and 4). Stability of the catalysts has been analyzed by IR, UV-spectroscopy and powder X-ray crystallography.

  19. Absolute quantification for benzoic acid in processed foods using quantitative proton nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Ohtsuki, Takashi; Sato, Kyoko; Sugimoto, Naoki; Akiyama, Hiroshi; Kawamura, Yoko

    2012-09-15

    The absolute quantification method of benzoic acid (BA) in processed foods using solvent extraction and quantitative proton nuclear magnetic resonance spectroscopy was developed and validated. BA levels were determined using proton signals (δ(H) 7.53 and 7.98) referenced to 2-dimethyl-2-silapentane-5-sulfonate-d(6) sodium salt (DSS-d(6)) after simple solvent extraction from processed foods. All recoveries from several kinds of processed foods, spiked at their specified maximum Japanese usage levels (0.6-2.5 g kg(-1)) and at 0.13 g kg(-1) and 0.063 g kg(-1), were greater than 80%. The limit of quantification was confirmed as 0.063 g kg(-1) in processed foods, which was sufficiently low for the purposes of monitoring BA. The accuracy of the proposed method is equivalent to the conventional method using steam-distillation extraction and high-performance liquid chromatography. The proposed method was both rapid and simple. Moreover, it provided International System of Units traceability without the need for authentic analyte standards. Therefore, the proposed method is a useful and practical tool for determining BA levels in processed foods.

  20. Metabolic Engineering of Pseudomonas putida KT2440 for the Production of para-Hydroxy Benzoic Acid

    Science.gov (United States)

    Yu, Shiqin; Plan, Manuel R.; Winter, Gal; Krömer, Jens O.

    2016-01-01

    para-Hydroxy benzoic acid (PHBA) is the key component for preparing parabens, a common preservatives in food, drugs, and personal care products, as well as high-performance bioplastics such as liquid crystal polymers. Pseudomonas putida KT2440 was engineered to produce PHBA from glucose via the shikimate pathway intermediate chorismate. To obtain the PHBA production strain, chorismate lyase UbiC from Escherichia coli and a feedback resistant 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase encoded by gene aroGD146N were overexpressed individually and simultaneously. In addition, genes related to product degradation (pobA) or competing for the precursor chorismate (pheA and trpE) were deleted from the genome. To further improve PHBA production, the glucose metabolism repressor hexR was knocked out in order to increase erythrose 4-phosphate and NADPH supply. The best strain achieved a maximum titer of 1.73 g L−1 and a carbon yield of 18.1% (C-mol C-mol−1) in a non-optimized fed-batch fermentation. This is to date the highest PHBA concentration produced by P. putida using a chorismate lyase. PMID:27965953

  1. Production of benzoic acid as a natural compound in fermented skim milk using commercial cheese starter.

    Science.gov (United States)

    Park, Sun-Young; Yoo, Mi-Young; Paik, Hyun-Dong; Lim, Sang-Dong

    2017-06-01

    In this study, we investigated the production of natural benzoic acid (BA) in skim milk fermentation by 5 kinds of commercial cheese starters. Five kinds of starter were inoculated into 10% reconstituted skim milk, and then the culture was incubated at 2-h intervals for 10 h at 30, 35, and 40°C. In fermentation by MW 046 N+LH 13, the starter for making raclette, BA was highly detected after 8 h at 30 and 35°C. In fermentation by LH 13, the starter for making berg, BA steadily increased and was highly detected at 40°C. In fermentation by TCC-3+TCC-4, the starter for making Caciocavallo and mozzarella, BA was detected after 2 h at 40°C. Also, BA was detected after 4 and 8 h at 35 and 30°C, respectively. In fermentation by Flora-Danica, the starter for making Gouda, BA was increased until 6 h and decreased after 6 h at all temperatures. Among the 5 kinds of fermentation, the level of BA was the highest in fermentation by Flora-Danica at 6 h at 35°C, at 14.55 mg/kg. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Mn(II) complexes with bipyridine, phenanthroline and benzoic acid: Biological and catalase-like activity

    Indian Academy of Sciences (India)

    Ibrahim Kani; Özlem Atlier; Kiymet Güven

    2016-04-01

    Five mononuclear Mn(II) complexes, [Mn(phen)2(ClO4)2] (1), [Mn(phen)3](ClO4)2(H2CO3)2(2), [Mn(bipy)2(ClO4)2] (3), [Mn(bipy)3](ClO4)2) (4), and Mn(phen)2(ba)(H2O)](ClO4)(CH3OH) (5), where bipy = 2,2’-bipyridine, phen = 1,10-phenanthroline, and ba = benzoic acid were prepared and characterized by Xray, IR and UV-Vis spectroscopies, and their catalase-like and biological activities were studied. The presence of two different types and the number of chelating NN-donor neutral ligands allowed for analysis of their effects on the catalase and biological activities. It was observed that the presence and number of phen ligands improved the activity more than the bipy ligand. Complexes 1 and 2, which contain more basic phen ligands, disproportionate H2O2 faster than complexes 3 and 4, which contain less basic bipy ligands. The in vitro antimicrobial activities of all the complexes were also tested against seven bacterial strains by microdilution tests. All the bacterial isolates demonstrated sensitivity to the complexes and the antifungal (anticandidal) activities of the Mn(II) complexes were remarkably higher than the reference drug ketoconazole.

  3. Self-Assembled Structures of Benzoic Acid on Au(111) Surface

    Science.gov (United States)

    Vu, Thu-Hien; Wandlowski, Thomas

    2017-02-01

    Electrochemical scanning tunneling microscopy combined with cyclic voltammetry were employed to explore the self-assembly of benzoic acid (BA) on a Au(111) substrate surface in a 0.1-M HClO4 solution. At the negatively charged surface, BA molecules form two highly ordered physisorbed adlayers with their phenyl rings parallel to the substrate surface. High-resolution scanning tunneling microscopy images reveal the packing arrangement and internal molecular structures. The striped pattern and zigzag structure of the BA adlayers are composed of parallel rows of dimers, in which two BA molecules are bound through a pair of O-H···O hydrogen bonds. Increasing the electrode potential further to positive charge densities of Au(111) leads to the desorption of the physisorbed hydrogen-bonded networks and the formation of a chemisorbed adlayer. BA molecules change their orientation from planar to upright fashion, which is accompanied by the deprotonation of the carboxyl group. Furthermore, potential-induced formation and dissolution of BA adlayers were also investigated. Structural transitions between the various types of ordered adlayers occur according to a nucleation and growth mechanism.

  4. Modified ferrous ammonium sulfate benzoic acid xyelenol orange (MFBX) and thermoluminescent dosimeters--a comparative study.

    Science.gov (United States)

    Brindha, S; Rose, J V R; Sathyan, S; Singh I, Rabi Raja; Ravindran, B Paul

    2002-06-07

    Radiation dosimetry deals with the determination of absorbed dose to the medium exposed to ionizing radiation. Chemical dosimetry depends on oxidation or reduction of chemicals by ionizing radiation. A ferrous ammonium sulfate benzoic acid xyelenol orange (FBX) dosimeter based on this principle is being used as a clinical dosimeter at present. Certain modifications were carried out in the preparation and storage of the FBX dosimeter to increase its shelf life. The resulting dosimeter was called a modified FBX (MFBX) dosimeter and has been used in our department for the past few years. An extensive study of the dose, dose rate and energy response of the dosimeter was carried out and compared with a thermoluminescent (LiF7) dosimeter. The results obtained were found to be comparable to the thermoluminescent (LiF7) dosimeter. Hence it was concluded that the MFBX dosimeter could be used for phantom dosimetry, data collection and in vivo measurements. Easier preparation and availability of the reagents are added advantages of using MFBX as a clinical dosimeter in small radiotherapy departments.

  5. Photoelectrocatalytic degradation of benzoic acid using Au doped TiO2 thin films.

    Science.gov (United States)

    Mohite, V S; Mahadik, M A; Kumbhar, S S; Hunge, Y M; Kim, J H; Moholkar, A V; Rajpure, K Y; Bhosale, C H

    2015-01-01

    Highly transparent pure and Au doped TiO2 thin films are successfully deposited by using simple chemical spray pyrolysis technique. The effect of Au doping onto the structural and physicochemical properties has been investigated. The PEC study shows that, both short circuit current (Isc) and open circuit voltage (Voc) are (Isc=1.81mA and Voc=890mV) relatively higher at 3at.% Au doping percentage. XRD study shows that the films are nanocrystalline in nature with tetragonal crystal structure. FESEM images show that the film surface covered with a smooth, uniform, compact and rice shaped nanoparticles. The Au doped thin films exhibit indirect band gap, decreases from 3.23 to 3.09eV with increase in Au doping. The chemical composition and valence states of pure and Au doped TiO2 films are studied by using X-ray photoelectron spectroscopy. The photocatalytic degradation effect is 49% higher in case 3at.% Au doped TiO2 than the pure TiO2 thin film photoelectrodes in the degradation of benzoic acid. It is revealed that Au doped TiO2 can be reused for five cycles of experiments without a requirement of post-treatment while the degradation efficiency was retained.

  6. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    Science.gov (United States)

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  7. Genetic dissection of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Geng, Peng; Xiao, Yin; Hu, Yun; Sun, Haiye; Xue, Wei; Zhang, Liang; Shi, Gui-Yang

    2016-09-01

    Dissection of the hereditary architecture underlying Saccharomyces cerevisiae tolerance to acetic acid is essential for ethanol fermentation. In this work, a genomics approach was used to dissect hereditary variations in acetic acid tolerance between two phenotypically different strains. A total of 160 segregants derived from these two strains were obtained. Phenotypic analysis indicated that the acetic acid tolerance displayed a normal distribution in these segregants, and suggested that the acetic acid tolerant traits were controlled by multiple quantitative trait loci (QTLs). Thus, 220 SSR markers covering the whole genome were used to detect QTLs of acetic acid tolerant traits. As a result, three QTLs were located on chromosomes 9, 12, and 16, respectively, which explained 38.8-65.9 % of the range of phenotypic variation. Furthermore, twelve genes of the candidates fell into the three QTL regions by integrating the QTL analysis with candidates of acetic acid tolerant genes. These results provided a novel avenue to obtain more robust strains.

  8. Omics analysis of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Geng, Peng; Zhang, Liang; Shi, Gui Yang

    2017-05-01

    Acetic acid is an inhibitor in industrial processes such as wine making and bioethanol production from cellulosic hydrolysate. It causes energy depletion, inhibition of metabolic enzyme activity, growth arrest and ethanol productivity losses in Saccharomyces cerevisiae. Therefore, understanding the mechanisms of the yeast responses to acetic acid stress is essential for improving acetic acid tolerance and ethanol production. Although 329 genes associated with acetic acid tolerance have been identified in the Saccharomyces genome and included in the database ( http://www.yeastgenome.org/observable/resistance_to_acetic_acid/overview ), the cellular mechanistic responses to acetic acid remain unclear in this organism. Post-genomic approaches such as transcriptomics, proteomics, metabolomics and chemogenomics are being applied to yeast and are providing insight into the mechanisms and interactions of genes, proteins and other components that together determine complex quantitative phenotypic traits such as acetic acid tolerance. This review focuses on these omics approaches in the response to acetic acid in S. cerevisiae. Additionally, several novel strains with improved acetic acid tolerance have been engineered by modifying key genes, and the application of these strains and recently acquired knowledge to industrial processes is also discussed.

  9. Effects of benzoic Acid and dietary calcium:phosphorus ratio on performance and mineral metabolism of weanling pigs.

    Science.gov (United States)

    Gutzwiller, A; Schlegel, P; Guggisberg, D; Stoll, P

    2014-04-01

    In a 2×2 factorial experiment the hypotheses tested were that the metabolic acid load caused by benzoic acid (BA) added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or 0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered. Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10). Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its implementation under practical feeding conditions.

  10. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  11. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  12. Adsorption of 2-X-benzoic acids (X = fluoro, chloro, and bromo) on Au(1 0 0) electrode in acidic media studied by IRAS

    Energy Technology Data Exchange (ETDEWEB)

    Ikezawa, Yasunari [Department of Chemistry, Faculty of Science, Rikkyo University, Nishi-Ikebukuro, Toshima-Ku, Tokyo 171 (Japan)]. E-mail: ikezawa@rikkyo.ac.jp; Yoshida, Atsushi [Department of Chemistry, Faculty of Science, Rikkyo University, Nishi-Ikebukuro, Toshima-Ku, Tokyo 171 (Japan); Ariga, Toshiyuki [Department of Chemistry, Faculty of Science, Rikkyo University, Nishi-Ikebukuro, Toshima-Ku, Tokyo 171 (Japan)

    2006-05-05

    Adsorption behaviors of 2-fluoro-, 2-chloro-, and 2-bromobenzoic acids on Au(1 0 0) electrode in 0.1 M HClO{sub 4} have been investigated by using in situ reflection adsorption IR spectroscopy and differential capacity measurements. It is found for the 2-substitued benzoic acids that the flat lying adsorbed species is present at negative potentials, and the vertically adsorbed benzoate with both oxygen atoms oriented toward the metal surface is present at positive potentials. A new adsorbed state due to the vertical orientation was observed around 0.75 V only in 2-fluorobenzoic acid solution, as well as the case of benzoic acid. This indicates that the new band is due to the formation of an ordered adsorption layer of the vertical 2-fluorobenzoate, and the formation of the arrangement adsorption is dependent on the size of the adsorbed molecule.

  13. Inhibitory effect of ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Wan, Wei; Wang, Jianlong [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China)

    2008-12-15

    The inhibitory effect of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 C and initial pH 7.0, during the fermentative hydrogen production, the substrate degradation efficiency, hydrogen production potential, hydrogen yield and hydrogen production rate all trended to decrease with increasing added ethanol, acetic acid, propionic acid and butyric acid concentration from 0 to 300 mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those of added acetic acid, propionic acid and butyric acid. The modified Han-Levenspiel model could describe the inhibitory effects of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production rate in this study successfully. The modified Logistic model could describe the progress of cumulative hydrogen production. (author)

  14. Methane-to-acetic acid synthesis matriculates at Penn State

    Energy Technology Data Exchange (ETDEWEB)

    Rotman, D.

    1994-04-20

    Direct conversion of methane to commercially valuable chemicals remains one of the grails of industrial chemistry. But scientists at Pennsylvania State University (University Park) appear to have made a significant step forward, reporting the direct catalytic conversion of methane into acetic acid under relatively mild conditions. Commercial acetic production involves a three-step process, including steam reforming of methane to synthesis gas (syngas) and the carbonylation of methanol of acetic acid.

  15. Isobaric Vapor-Liquid Equilibrium of Binary Systems: p-Xylene + (Acetic Acid, Methyl Acetate and n-Propyl Acetate)and Methyl Acetate + n-Propyl Acetate in an Acetic Acid Dehydration Process

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiuhui; ZHONG Weimin; PENG Changjun; QIAN Feng

    2013-01-01

    The vapor-liquid equilibrium data of four binary systems(acetic acid + p-xylene,methyl acetate + n-propyl acetate,n-propyl acetate + p-xylene and methyl acetate + p-xylene)are measured at 101.33 kPa with Ellis equilibrium still,and then both the NRTL and UNIQUAC models are used in combination with the HOC model for correlating and estimating the vapor-liquid equilibrium of these four binary systems.The estimated binary VLE results using correlated parameters agree well with the measured data except the methyl acetate + p-xylene system which easily causes bumping and liquid rushing out of the sampling tap due to their dramatically different boiling points.The correlation results by NRTL and UNIQUAC models have little difference on the average absolute deviations of temperature and composition of vapor phase,and the results by NRTL model are slightly better than those by UNIQUAC model except for the methyl acetate + n-propyl acetate system,for which the latter gives more accurate correlations.

  16. Biological Function of Acetic Acid-Improvement in Obesity and Glucose Tolerance by Acetic Acid in Type 2 Diabetic Rats.

    Science.gov (United States)

    Yamashita, Hiromi

    2016-07-29

    Fatty acids derived from adipose tissue are oxidized by β-oxidation to form ketone bodies as final products under the starving condition. Previously, we found that free acetic acid was formed concomitantly with the production of ketone bodies in isolated rat liver perfusion, and mitochondrial acetyl CoA hydrolase was appeared to be involved with the acetic acid production. It was revealed that acetic acid was formed as a final product of enhanced β-oxidation of fatty acids and utilized as a fuel in extrahepatic tissues under the starving condition. Under the fed condition, β-oxidation is suppressed and acetic acid production is decreased. When acetic acid was taken daily by obesity-linked type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats under the fed condition, it protected OLETF rats against obesity. Furthermore, acetic acid contributed to protect from the accumulation of lipid in the liver as well as abdominal fat in OLETF rats. Transcripts of lipogenic genes in the liver were decreased, while transcripts of myoglobin and Glut4 genes in abdominal muscles were increased in the acetic acid-administered OLETF rats. It is indicated that exogenously administered acetic acid would have effects on lipid metabolism in both the liver and the skeletal muscles, and have function that works against obesity and obesity-linked type 2 diabetes.

  17. Syntheses and fluorescent properties of complexes of Eu(Ⅲ) with HTTA,TPPO and benzoic acid

    Institute of Scientific and Technical Information of China (English)

    ZHAN Xuehui; XIAO Zhongliang; ZHAN Hanhui; ZHAO Xuehui; ZHOU Suian; LI Fei

    2009-01-01

    A series of Eu(Ⅲ) complexes of α-thenoyltrifluoroacetone(HTTA) with trioctylphosphine oxide(TPPO) and benzoic acid(BA) or its two derivatives, p-toluic acid(PTA) and p-methoxybenzoic acid(POA) were synthesized and were characterized with elemental analysis, IR spectroscopy, scanning electronic microscopy and fluorescent spectra. The complexes were revealed to be Eu(BA)(TTA)2TPPO2, Eu(PTA)(TTA)2TPPO2 and Eu(POA)(TTA)2TPPO2. The excitation and absorption spectra of the complex Eu(POA)(TTA)2TPPO2 in MeOH solution were investigated in detail. The experimental result showed that relatively cheap materials with sharp red luminescence could be pre-pared, when benzoic acid or its two derivatives were added in Eu(Ⅲ) complexes of α-thenoyltdfluoroacetone with trioctylphosphine oxide. The relative fluorescence intensity of the Eu(Ⅲ) complexes decreased in the following order: Eu(POA)(TTA)2TPPO2> Eu(PTA)(TTA)2TPPO2>Eu(BA)(TTA)2TPPO2.

  18. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    Science.gov (United States)

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  19. Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica.

    Science.gov (United States)

    Ehsanipour, Mandana; Suko, Azra Vajzovic; Bura, Renata

    2016-06-01

    A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process.

  20. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  1. Inhibitors of HIV-1 maturation: Development of structure-activity relationship for C-28 amides based on C-3 benzoic acid-modified triterpenoids.

    Science.gov (United States)

    Swidorski, Jacob J; Liu, Zheng; Sit, Sing-Yuen; Chen, Jie; Chen, Yan; Sin, Ny; Venables, Brian L; Parker, Dawn D; Nowicka-Sans, Beata; Terry, Brian J; Protack, Tricia; Rahematpura, Sandhya; Hanumegowda, Umesh; Jenkins, Susan; Krystal, Mark; Dicker, Ira B; Meanwell, Nicholas A; Regueiro-Ren, Alicia

    2016-04-15

    We have recently reported on the discovery of a C-3 benzoic acid (1) as a suitable replacement for the dimethyl succinate side chain of bevirimat (2), an HIV-1 maturation inhibitor that reached Phase II clinical trials before being discontinued. Recent SAR studies aimed at improving the antiviral properties of 2 have shown that the benzoic acid moiety conferred topographical constraint to the pharmacophore and was associated with a lower shift in potency in the presence of human serum albumin. In this manuscript, we describe efforts to improve the polymorphic coverage of the C-3 benzoic acid chemotype through modifications at the C-28 position of the triterpenoid core. The dimethylaminoethyl amides 17 and 23 delivered improved potency toward bevirimat-resistant viruses while increasing C24 in rat oral PK studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S.

    1984-01-01

    Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

  3. Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S.

    1984-01-01

    Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

  4. Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

    Institute of Scientific and Technical Information of China (English)

    CHENG Youwei; HUO Lei; LI Xi

    2013-01-01

    The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel.The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 =0 to 1.A new method to measure the solubility was developed,which solved the problem of sampling at high temperature.The experimental results indicated that within the temperature range studied,the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature.The experimental solubilities were correlated by the Buchowski equation,and the calculate results showed good agreement with the experimental solubilities.Furthermore,the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility,which may be attributed to the intermolecular association between the solute and the solvent mixture.The maximum solubility effect was well modeled by the modified Wilson equation.

  5. Aqueous high-temperature chemistry of carbo- and heterocycles. 2. Monosubstituted benzenes: Benzyl alcohol, benzaldehyde, and benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Katritzky, A.R.; Balasubramanian, M. (Univ. of Florida, Gainesville (USA)); Siskin, M. (Exxon Research and Engineering Company, Annandale, NJ (USA))

    Benzyl alcohol is not very reactive under aquathermolysis conditions, except in the presence of acids. Almost all the products are formed by ionic pathways. It undergoes reversible dehydration to dibenzyl ether, disproportionation to benzaldehyde and toluene, and self-benzylation to 2- and 4-benzylbenzyl alcohols. These benzylbenzyl alcohols can react further, but major amounts of polyalkylated products are formed by the mono- and dibenzylation of toluene to give a range of dibenzyltoluenes and (benzylbenzyl)toluenes. Small amounts of diphenylmethane and bibenzyl and their benzylated products are also formed. The behavior of benzyl alcohol in the presence of phenol, pyridine, benzaldehyde, and benzene is also studied and rationalized. Benzaldehyde is much less reactive, except in the presence of formaldehyde, and especially in the presence of formic acid, when considerable formation of benzyl alcohol occurs and siphoning into this reaction matrix is observed. Benzoic acid is still less reactive.

  6. Probiotic and Acetic Acid Effect on Broiler Chickens Performance

    OpenAIRE

    Martin Král; Mária Angelovičová; Ľubica Mrázová; Jana Tkáčová; Martin Kliment

    2011-01-01

    Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drin...

  7. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor

    OpenAIRE

    Majid MOUNIR; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-01-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV...

  8. DETERMINATION OF URINE PH AND AMMONIA EMISSION AFTER ADDITION OF BENZOIC ACID AND DRIED BEET PULP IN GROWING PIGS

    Directory of Open Access Journals (Sweden)

    Peter Patráš

    2013-02-01

    Full Text Available Twelve crossbred gilts (initial BW 29.9 ± 1.7 kg were used for evalution of the effect of benzoic acid and the fiber in diets on the urinary pH, ammonia of the slurry and redistribution of nitrogen between faeces and urinary. For the pigs there were randomly allotted three dietary treatments according to a replicated 3 x 3 Latin square design. The dietary treatments included: Diet control (C was supplemented with isoleucine, lysine, methionine, threonine, tryptophan, and valine to fulfill the requirements of ideal amino acid profile; diet (BA was similar to diet (C with 10g.kg-1 benzoic acid; diet (BABP was similar to diet (C with 10g.kg-1 benzoic acid and 150 g.kg-1 dried beet pulp, all of them with equal ME content (13.3 MJ/kg and supplemented with rapeseed oil. The pigs were housed in metabolic cages and fed with two equal doses at 7 a.m. and 5 p.m. at a daily rate of 90 g. kg0.75. Water was offered ad libitum. Each experimental period consisted of a 6-d adaptation phase and was followed by a 4-d collection phase. During collection phase the feces and the urine (using bladder catheters were collected. The experimental data were subjected to ANOVA and when significant value for treatment effect (P<0.05 was observed, the differences between means were assessed with using Fisher's LSD procedure. Nitrogen and dry matter intake was not significantly affected by any of the feed additives. Nitrogen and dry matter intake was not significantly affected by any of supplemented additives. Fecal N excretion was increased (P <0.02 in pigs fed with added fiber (BABP, in the same group there was detected the reduction of urinary N excretion (P< 0.04. There was significant decrease of urine pH, concretely by three quarters of pH point in the both experimental groups fed with bonzoic acid diets, regardless of the fiber content in the diet. The coefficients of excretion determination between hippuric acid and urine pH were R2 = 0.298. The same decrease of

  9. Benzoic and sorbic acid in soft drink, milk, ketchup sauce and bread by dispersive liquid-liquid microextraction coupled with HPLC.

    Science.gov (United States)

    Javanmardi, Fardin; Nemati, Mahboob; Ansarin, Masood; Arefhosseini, Seyyed Rafie

    2015-01-01

    Benzoic acid and sorbic acid are widely used for food preservation. These preservatives are generally recognised as safe. The aim of this study was to determine the level of benzoic and sorbic acid in food samples that are usually consumed in Iran. Therefore, 54 samples, including 15 soft drinks, 15 ultra-high-temperature milk, 15 ketchup sauces and 9 bread samples, were analysed by high-performance liquid chromatography with UV detection. Benzoic acid was detected in 50 (92.5%) of the samples ranging from 3.5 to 1520 µg mL⁻¹, while sorbic acid was detected in 29 (50.3%) samples in a range of 0.8 and 2305 µg mL⁻¹. Limits of detection and limits of quantification for benzoate were found to be 0.1 and 0.5 µg mL⁻¹, respectively, and for sorbate 0.08 and 0.3 µg mL⁻¹, respectively. The results showed that benzoic acid and sorbic acid widely occur in food products in Iran.

  10. 苯甲酸釜残液全部回收的工艺开发利用%Development on the Technique of Total Recovery of Benzoic Acid Residue

    Institute of Scientific and Technical Information of China (English)

    徐姣; 何杰; 张卫江; 杨焘; 焦书军; 胡雪东

    2009-01-01

    Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene. Because it contained important chemical raw materials such as benzoic acid, benzyl benzoate and fluorenone, it is necessary to recover them from the residue. In this work the technique featured with high efficiency evaporation and vacuum distillation was developed to obtain total recovery and utilization of the benzoic acid residue. By con-trolling the operation temperature at 260℃ and the pressure of 16 kPa in the rising and falling film evaporators, heavy components separated efficiently from the residue can be polymerized and the light components consisting of 63% of the residue entered into a benzoic acid vacuum distillation column. Keeping the temperature of polymeriza-tion at (280±10)℃, coumarone resin was produccd after adjusting the softening point according to the market re-quirements. Vacuum distillation was operated under the following conditions: top temperature at 186℃, top pres-sure of 16 kPa, bottom temperature at 240 250℃, reflux ratio being 3:1. Benzoic acid of 98% purity was distilled out from the column as a side stream and the bottom product was crude benzyl benzoate. By the developed tech-nique, the benzoic acid residue was splitted into three products, benzoic acid, crude benzyl benzoate and coumarone resin without any surplus waste.

  11. Quantification of tetrabromo benzoic acid and tetrabromo phthalic acid in rats exposed to the flame retardant Uniplex FPR-45.

    Science.gov (United States)

    Silva, Manori J; Hilton, Donald; Furr, Johnathan; Gray, L Earl; Preau, James L; Calafat, Antonia M; Ye, Xiaoyun

    2016-03-01

    The first withdrawal of certain polybrominated diphenyl ethers flame retardants from the US market occurred in 2004. Since then, use of brominated non-PBDE compounds such as bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) in commercial formulations has increased. Assessing human exposure to these chemicals requires identifying metabolites that can potentially serve as their biomarkers of exposure. We administered by gavage a dose of 500 mg/Kg bw of Uniplex FRP-45 (>95 % BEH-TEBP) to nine adult female Sprague-Dawley rats. Using authentic standards and mass spectrometry, we positively identified and quantified 2,3,4,5-tetrabromo benzoic acid (TBBA) and 2,3,4,5-tetrabromo phthalic acid (TBPA) in 24-h urine samples collected 1 day after dosing the rats and in serum at necropsy, 2 days post-exposure. Interestingly, TBBA and TBPA concentrations correlated well (R (2) = 0.92). The levels of TBBA, a known metabolite of EH-TBB, were much higher than the levels of TBPA both in urine and serum. Because Uniplex FRP-45 was technical grade and EH-TBB was present in the formulation, TBBA likely resulted from the metabolism of EH-TBB. Taken together, our data suggest that TBBA and TBPA may serve as biomarkers of exposure to non-PBDE brominated flame retardant mixtures. Additional research can provide useful information to better understand the composition and in vivo toxicokinetics of these commercial mixtures.

  12. Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Zhi Guo Song; Hong Gong; Heng Jiang

    2008-01-01

    Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and mused many times. The reaction was mild and efficient with good to high yields.

  13. Disproportionation Kinetics of Hypoiodous Acid As Catalyzed and Suppressed by Acetic Acid-Acetate Buffer.

    Science.gov (United States)

    Urbansky, Edward T.; Cooper, Brian T.; Margerum, Dale W.

    1997-03-26

    The kinetics of the disproportionation of hypoiodous acid to give iodine and iodate ion (5HOI right harpoon over left harpoon 2I(2) + IO(3)(-) + H(+) + 2H(2)O) are investigated in aqueous acetic acid-sodium acetate buffer. The rate of iodine formation is followed photometrically at -log [H(+)] = 3.50, 4.00, 4.50, and 5.00, &mgr; = 0.50 M (NaClO(4)), and 25.0 degrees C. Both catalytic and inhibitory buffer effects are observed. The first process is proposed to be a disproportionation of iodine(I) to give HOIO and I(-); the iodide then reacts with HOI to give I(2). The reactive species (acetato-O)iodine(I), CH(3)CO(2)I, is postulated to increase the rate by assisting in the formation of I(2)O, a steady-state species that hydrolyzes to give HOIO and I(2). Inhibition is postulated to result from the formation of the stable ion bis(acetato-O)iodate(I), (CH(3)CO(2))(2)I(-), as buffer concentration is increased. This species is observed spectrophotometrically with a UV absorption shoulder (lambda = 266 nm; epsilon = 530 M(-)(1) cm(-)(1)). The second process is proposed to be a disproportionation of HOIO to give IO(3)(-) and I(2). Above 1 M total buffer, the reaction becomes reversible with less than 90% I(2) formation. Rate and equilibrium constants are resolved and reported for the proposed mechanism.

  14. Synthesis, characterization and biocidal activity of new organotin complexes of 2-(3-oxocyclohex-1-enyl)benzoic acid.

    Science.gov (United States)

    Vieira, Flaviana T; de Lima, Geraldo M; Maia, José R da S; Speziali, Nivaldo L; Ardisson, José D; Rodrigues, Leonardo; Correa, Ary; Romero, Oscar B

    2010-03-01

    The reaction of 1,3-cyclohexadione with 2-aminobenzoic acid has produced the 2-(3-oxocyclohex-1-enyl)benzoic acid (HOBz). Subsequent reactions of the ligand with organotin chlorides led to [Me(2)Sn(OBz)O](2) (1), [Bu(2)Sn(OBz)O](2) (2), [Ph(2)Sn(OBz)O](2) (3), [Me(3)Sn(OBz)] (4), [Bu(3)Sn(OBz)] (5) and [Ph(3)Sn(OBz)] (6). All complexes have been fully characterized. In addition the structure of complexes (2) and (4) have been authenticated by X-ray crystallography. The biological activity of all derivatives has been screened against Cryptococcus neoformans and Candida albicans. In addition we have performed toxicological testes employing human kidney cell. The complexes (3), (5) and (6) displayed the best values of inhibition of the fungus growing, superior to ketoconazole. Compound (5) presented promising results in view of the antifungal and cytotoxicity assays.

  15. Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures

    Directory of Open Access Journals (Sweden)

    B. A. Mandagarán

    2006-03-01

    Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

  16. Benzoic acid fermentation from starch and cellulose via a plant-like β-oxidation pathway in Streptomyces maritimus

    Directory of Open Access Journals (Sweden)

    Noda Shuhei

    2012-04-01

    Full Text Available Abstract Background Benzoic acid is one of the most useful aromatic compounds. Despite its versatility and simple structure, benzoic acid production using microbes has not been reported previously. Streptomyces are aerobic, Gram-positive, mycelia-forming soil bacteria, and are known to produce various kinds of antibiotics composed of many aromatic residues. S. maritimus possess a complex amino acid modification pathway and can serve as a new platform microbe to produce aromatic building-block compounds. In this study, we carried out benzoate fermentation using S. maritimus. In order to enhance benzoate productivity using cellulose as the carbon source, we constructed endo-glucanase secreting S. maritimus. Results After 4 days of cultivation using glucose, cellobiose, or starch as a carbon source, the maximal level of benzoate reached 257, 337, and 460 mg/l, respectively. S. maritimus expressed β-glucosidase and high amylase-retaining activity compared to those of S. lividans and S. coelicolor. In addition, for effective benzoate production from cellulosic materials, we constructed endo-glucanase-secreting S. maritimus. This transformant efficiently degraded the phosphoric acid swollen cellulose (PASC and then produced 125 mg/l benzoate. Conclusions Wild-type S. maritimus produce benzoate via a plant-like β-oxidation pathway and can assimilate various carbon sources for benzoate production. In order to encourage cellulose degradation and improve benzoate productivity from cellulose, we constructed endo-glucanase-secreting S. maritimus. Using this transformant, we also demonstrated the direct fermentation of benzoate from cellulose. To achieve further benzoate productivity, the L-phenylalanine availability needs to be improved in future.

  17. Comparison of visual inspection with acetic acid (via) with ...

    African Journals Online (AJOL)

    Comparison of visual inspection with acetic acid (via) with papanicolaou ... Abstract. Background: Cervical cancer is the second most common killer ... VIA while 10 (4.2%) had heard about Pap smear test as a screening test for cervical cancer.

  18. In situ N{sub 2}O emissions are not mitigated by hippuric and benzoic acids under denitrifying conditions

    Energy Technology Data Exchange (ETDEWEB)

    Krol, D.J., E-mail: dominika.krol@teagasc.ie; Forrestal, P.J.; Lanigan, G.J.; Richards, K.G.

    2015-04-01

    Ruminant urine patches deposited onto pasture are a significant source of greenhouse gas nitrous oxide (N{sub 2}O) from livestock agriculture. Increasing food demand is predicted to lead to a rise in ruminant numbers globally, which, in turn will result in elevated levels of urine-derived N{sub 2}O. Therefore mitigation strategies are urgently needed. Urine contains hippuric acid and together with one of its breakdown products, benzoic acid, has previously been linked to mitigating N{sub 2}O emissions from urine patches in laboratory studies. However, the sole field study to date found no effect of hippuric and benzoic acid concentration on N{sub 2}O emissions. Therefore the aim of this study was to investigate the in situ effect of these urine constituents on N{sub 2}O emissions under conditions conducive to denitrification losses. Unadulterated bovine urine (0 mM of hippuric acid, U) was applied, as well as urine amended with either benzoic acid (96 mM, U + BA) or varying rates of hippuric acid (8 and 82 mM, U + HA1, U + HA2). Soil inorganic nitrogen (N) and N{sub 2}O fluxes were monitored over a 66 day period. Urine application resulted in elevated N{sub 2}O flux for 44 days. The largest N{sub 2}O fluxes accounting for between 13% (U) and 26% (U + HA1) of total loss were observed on the day of urine application. Between 0.9 and 1.3% of urine-N was lost as N{sub 2}O. Cumulative N{sub 2}O loss from the control was 0.3 kg N{sub 2}O–N ha{sup −1} compared with 11, 9, 12, and 10 kg N{sub 2}O–N ha{sup −1} for the U, U + HA1, U + HA2, and U + BA treatments, respectively. Incremental increases in urine HA or increase in BA concentrations had no effect on N{sub 2}O emissions. Although simulation of dietary manipulation to reduce N{sub 2}O emissions through altering individual urine constituents appears to have no effect, there may be other manipulations such as reducing N content or inclusion of synthetic inhibitory products that warrant further investigation

  19. A NOVEL COPOLYMER-BOUND CIS- DICARBONYLRHODIUM COMPLEX FOR THE CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    YUAN Guoqing; CHEN Yuying; CHEN Rongyao

    1989-01-01

    A series of porous microspheres of linear and ethylene diacrylate (M ') cross-linked copolymers of 2 - vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol - acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.

  20. Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey proteins.

    Science.gov (United States)

    Listiyani, M A D; Campbell, R E; Miracle, R E; Dean, L O; Drake, M A

    2011-09-01

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations in dried whey products. No legal limit exists in the United States for BP use in whey, but international concerns exist. The objectives of this study were to determine the effect of hydrogen peroxide (HP) or BP bleaching on the flavor of 34% WPC (WPC34) and to evaluate residual BA in commercial and experimental WPC bleached with and without BP. Cheddar whey was manufactured in duplicate. Pasteurized fat-separated whey was subjected to hot bleaching with either HP at 500 mg/kg, BP at 50 or 100 mg/kg, or no bleach. Whey was ultrafiltered and spray dried into WPC34. Color [L*(lightness), a* (red-green), and b* (yellow-blue)] measurements and norbixin extractions were conducted to compare bleaching efficacy. Descriptive sensory and instrumental volatile analyses were used to evaluate bleaching effects on flavor. Benzoic acid was extracted from experimental and commercial WPC34 and 80% WPC (WPC80) and quantified by HPLC. The b* value and norbixin concentration of BP-bleached WPC34 were lower than HP-bleached and control WPC34. Hydrogen peroxide-bleached WPC34 displayed higher cardboard flavor and had higher volatile lipid oxidation products than BP-bleached or control WPC34. Benzoyl peroxide-bleached WPC34 had higher BA concentrations than unbleached and HP-bleached WPC34 and BA concentrations were also higher in BP-bleached WPC80 compared with unbleached and HP-bleached WPC80, with smaller differences than those observed in WPC34. Benzoic acid extraction from permeate showed that WPC80 permeate contained more BA than did WPC34 permeate. Benzoyl peroxide is more effective in color removal of whey and results in fewer flavor side effects compared with HP and residual BA is

  1. Genetic organization of Acetobacter for acetic acid fermentation.

    Science.gov (United States)

    Beppu, T

    Plasmid vectors for the acetic acid-producing strains of Acetobacter and Gluconobacter were constructed from their cryptic plasmids and the efficient transformation conditions were established. The systems allowed to reveal the genetic background of the strains used in the acetic acid fermentation. Genes encoding indispensable components in the acetic acid fermentation, such as alcohol dehydrogenase, aldehyde dehydrogenase and terminal oxidase, were cloned and characterized. Spontaneous mutations at high frequencies in the acetic acid bacteria to cause the deficiency in ethanol oxidation were analyzed. A new insertion sequence element, IS1380, was identified as a major factor of the genetic instability, which causes insertional inactivation of the gene encoding cytochrome c, an essential component of the functional alcohol dehydrogenase complex. Several genes including the citrate synthase gene of A. aceti were identified to confer acetic acid resistance, and the histidinolphosphate aminotransferase gene was cloned as a multicopy suppressor of an ethanol sensitive mutant. Improvement of the acetic acid productivity of an A. aceti strain was achieved through amplification of the aldehyde dehydrogenase gene with a multicopy vector. In addition, spheroplast fusion of the Acetobacter strains was developed and applied to improve their properties.

  2. Optical dephasing by uncorrelated phonon scattering to librations. An optical and picosecond photon echo study of a photosite of pentacene in benzoic acid

    NARCIS (Netherlands)

    Molenkamp, L.W.; Wiersma, Douwe A.

    1984-01-01

    We report results of an optical and picosecond photon echo study on the zero-phonon line of photosite I of pentacene in benzoic acid. The results show that optical dephasing in this system proceeds via uncorrelated phonon scattering processes from the ground and optically excited state to singly exc

  3. Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

    Science.gov (United States)

    Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

    2012-03-16

    Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining.

  4. Synthesis and Properties of Dimesogenic Compounds Containing Cholesterol and 4-(trans-4-n-Alkylcyclohexyl)- benzoic Acid Moieties

    Institute of Scientific and Technical Information of China (English)

    YU, Haibo; HOU, Ruibin; CHEN, Tie; YIN, Bingzhu; MUHAMMAD, Jamil; JEON, Youngja

    2009-01-01

    A series of novel dimesogenic compounds containing cholesterol and 4-(trans-4-n-alkylcyclohexyl)benzoic acid moieties were synthesized. The two mesogenic units of these compounds are linked with ω-oxyalkanoyl spacers of varying lengths. The chemical structure and mesomorphic properties of this series of compounds were characterized by FT-IR, MS, 1H NMR, polarizing optical microscopy (POM) and DSC techniques. The average viscosity and helical twisting power (HTP) in host liquid crystals of selected dimesogenic compounds were also measured. It was found that most of the present novel series of compounds exhibited only cholesteric mesophase with lower phase transition temperatures, and the average viscosity and HTP of selected compounds were similar to or superior to cholesteryl nonylate.

  5. Experimental investigation of benzoic acid diffusion coefficient in γ-Al2O3 nanofluids at different temperatures

    Science.gov (United States)

    Manouchehrian Fard, Manouchehr; Beiki, Hossein

    2016-10-01

    An experimental study was performed to measure benzoic acid diffusion coefficient in water-based γ-Al2O3 nanofluids at different temperatures. Measurements were carried out at 15, 20 and 25 °C. γ-Al2O3 nanoparticles with an average diameter of 10-20 nm were added into de-ionized water as the based fluid. Nanoparticles volume fractions used in the based fluid were 0.025, 0.05, 0.1, 0.2, 0.4 and 0.8 %. Measurements showed that the diffusion coefficients was not changed with nanoparticles concentration and no enhancement was found. Dependence of diffusion coefficients on nanoparticles concentration followed the same trend in all temperatures investigated in this work. Nano stirring and nano-obstacles could be regarded as two reasons for mass diffusivity changes in nanofluids.

  6. Spectroscopic studies on the interaction between norfloxacin and p-amino benzoic acid: Analytical application on determination of norfloxacin

    Science.gov (United States)

    More, V. R.; Mote, U. S.; Patil, S. R.; Kolekar, G. B.

    2009-10-01

    Fluorescence (Förster) Resonance Energy Transfer (FRET) between norfloxacin (NF) and p-amino benzoic acid (PABA) has been investigated by fluorescence and UV-vis absorption spectroscopy. It was found that the quenching of fluorescence of PABA is followed by simultaneous sensitization of NF fluorescence. The hydrophobic and electrostatic interaction plays an important role to stabilize the complex. The binding constant ( K), binding site number ( n) and corresponding thermodynamic parameters like free energy change (Δ G), enthalpy change (Δ H) and entropy change (Δ S) were determined according to van't Hoff equation. Using FRET, the distance ( r) between donor (PABA) and acceptor (NF) was obtained. This method is simple, selective and relatively free of interference from co-existing substances. The method was successfully applied to the determination of norfloxacin from pharmaceutical tablets.

  7. Identification of robust synthon in the molecular salts of 2-aminothiazole with substituted benzoic acids: A case stu

    Indian Academy of Sciences (India)

    Madhavi Oruganti; Raghavaiah Pallepogu; Darshak R Trivedi

    2014-09-01

    Six new salts of an API intermediate 2-aminothiazole with different carboxylic acid coformers were synthesized and characterized by IR (Infrared spectroscopy), 1H-NMR, DSC (Differential scanning calorimetry), XRPD (X-ray powder diffraction) and single crystal XRD. The crystal structure of the salts with benzoic acid, 2,3-, 2,4-, 2,5-, 2,6- dihydroxybenzoic acids and 2,4-dinitrobenzoic acid were determined. The thiazole moiety exhibited solvent (polarity) assisted tautomerism in all reported salts and proton transfer was noticed to the ring N of thiazole due to which two point supramolecular synthon N+−H(thiazole)…O−(acid), N−H(amine)…O−(acid) was observed. The crystal structures were studied with respect to the positional effect of the competing functional groups like hydroxyl (−OH) and nitro (−NO2) as well as their donor and acceptor abilities for hydrogen bonding. The presence of the non-conventional hydrogen bond (C−H…O) has been found to play a critical role in the formation of secondary supramolecular architectures.

  8. Encapsulation of 4-hydroxy-3-methoxy benzoic acid and 4-hydroxy-3,5-dimethoxy benzoic acid with native and modified cyclodextrins

    Science.gov (United States)

    Rajendiran, N.; Jude Jenita, M.

    2015-02-01

    Inclusion complex formation of 4-hydroxy-3-methoxybenzoic acid (HMBA) and 4-hydroxy-3,5-dimethoxybenzoic acid (HDMBA) with α-CD, β-CD, HP-α-CD and HP-β-CD were studied by absorption, steady state fluorescence, time resolved fluorescence, FT-IR, 1H NMR and molecular modeling methods. The effect of the CDs with HMBA and HDMBA were studied in pH ∼ 1, pH ∼ 7 and pH ∼ 10 buffer solutions. The study revealed that both hydroxybenzoic acids formed 1:1 complex with the four CDs. The theoretical values suggest that both guests are partially encapsulated into the CDs cavity. The hydroxy group is present in the interior part of the CD cavity and carboxyl group is present in the hydrophilic part of the CD cavity. Molecular modeling studies proved that (i) the negative Gibbs energy and enthalpy changes for the inclusion complexes indicated that the formation of these complexes were spontaneous and exothermic, (ii) hydrogen bonding interactions played a major role in the inclusion process, (iii) the dipole moment values for guests increased when they entered into the CDs cavities which is an indication of the increase of the polarity and the formation of complex and (iv) differences in binding energy and enthalpy change suggest that the β-CD formed more stable complex than α-CD.

  9. Synthesis of imidazol-1-yl-acetic acid hydrochloride: A key intermediate for zoledronic acid

    OpenAIRE

    Singh, Santosh Kumar; Manne, Narendra; Ray, Purna Chandra; Pal, Manojit

    2008-01-01

    A convenient and practical synthesis of imidazol-1-yl-acetic acid hydrochloride was achieved via N-alkylation of imidazole using tert-butyl chloroacetate followed by a non-aqueous ester cleavage of the resulting imidazol-1-yl-acetic acid tert-butyl ester in the presence of titanium tetrachloride. The synthesized imidazol-1-yl-acetic acid hydrochloride was then utilized to prepare zoledronic acid.

  10. Synthesis of imidazol-1-yl-acetic acid hydrochloride: A key intermediate for zoledronic acid

    Science.gov (United States)

    Manne, Narendra; Ray, Purna Chandra

    2008-01-01

    Summary A convenient and practical synthesis of imidazol-1-yl-acetic acid hydrochloride was achieved via N-alkylation of imidazole using tert-butyl chloroacetate followed by a non-aqueous ester cleavage of the resulting imidazol-1-yl-acetic acid tert-butyl ester in the presence of titanium tetrachloride. The synthesized imidazol-1-yl-acetic acid hydrochloride was then utilized to prepare zoledronic acid. PMID:19104672

  11. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic acid...

  12. Kinetics and Mechanism of Oxidation of Phenyl Acetic Acid and Dl-Mandelic Acid by Permanganate in Acid Medium

    Directory of Open Access Journals (Sweden)

    B.Syama Sundar

    2014-06-01

    Full Text Available Kinetics of oxidation of phenyl acetic acid and DL- Mandelic acid by potassium permanganate in aqueous acetic acid and perchloric acid mixture reveals that the kinetic orders are first order in oxidant, first order in H+ and zero order in substrate for phenyl acetic acid. DL-Mandelic acid exhibits first order in oxidant and zero order in substrate. The results are rationalised by a mechanism involving intermediate formation of mandelic acid in case of Phenyl acetic acid and ester formation with Mn (VII in case of DL-Mandelic acid. The following order of reactivity is observed: DL-Mandelic acid > Phenyl acetic acid. The high reactivity of DL-Mandelic acid over phenyl acetic acid may be due to different mechanisms operating with the two substrates and benzaldehyde is the final product in both the cases.

  13. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    Science.gov (United States)

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-08

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016.

  14. Fischer indolisation of N-(α-ketoacyl)anthranilic acids into 2-(indol-2-carboxamido)benzoic acids and 2-indolyl-3,1-benzoxazin-4-ones and their NMR study.

    Science.gov (United States)

    Proisl, Karel; Kafka, Stanislav; Urankar, Damijana; Gazvoda, Martin; Kimmel, Roman; Košmrlj, Janez

    2014-12-21

    N-(α-ketoacyl)anthranilic acids reacted with phenylhydrazinium chloride in boiling acetic acid to afford 2-(indol-2-carboxamido)benzoic acids in good to excellent yields and 2-indolyl-3,1-benzoxazin-4-ones as by-products. The formation of the latter products could easily be suppressed by a hydrolytic workup. Alternatively, by increasing the reaction temperature and/or time, 2-indolyl-3,1-benzoxazin-4-ones can be obtained exclusively. Optimisations of the reaction conditions as well as the scope and the course of the transformations were investigated. The products were characterized by (1)H, (13)C and (15)N NMR spectroscopy. The corresponding resonances were assigned on the basis of the standard 1D and gradient selected 2D NMR experiments ((1)H-(1)H gs-COSY, (1)H-(13)C gs-HSQC, (1)H-(13)C gs-HMBC) with (1)H-(15)N gs-HMBC as a practical tool to determine (15)N NMR chemical shifts at the natural abundance level of (15)N isotope.

  15. Homologous series of low molecular weight (C1-C10) monocarboxylic acids, benzoic acid and hydroxyacids in fine-mode (PM2.5) aerosols over the Bay of Bengal: Influence of heterogeneity in air masses and formation pathways

    Science.gov (United States)

    Boreddy, Suresh K. R.; Mochizuki, Tomoki; Kawamura, Kimitaka; Bikkina, Srinivas; Sarin, M. M.

    2017-10-01

    Low molecular weight monocarboxylic acids (LMW monoacids) are most abundant volatile organic compounds (VOCs) in the atmosphere and often act as important contributors to the acidity of precipitation in addition to inorganic acids. However, there is a large uncertainty in the sources and secondary formations of these acids in the atmosphere. This study reports homologous series of LMW monoacids, including normal (C1-C10), branched chain (iC4-iC6), aromatic (benzoic acid) and hydroxyacids (lactic and glycolic acids) in the fine-mode (PM2.5) aerosols collected over the Bay of Bengal (BoB) during a winter cruise (December 2008 to January 2009). The samples were associated with two distinct continental air masses arriving from the Indo-Gangetic Plain (IGP-outflow) and Southeast Asia (SEA-outflow). The molecular distributions of organic acids are characterized by the dominance of formic acid (C1) followed by acetic acid (C2) and nonanoic acid (C9) in the IGP-outflow, whereas dominance of C1 or C9 was observed in the SEA-outflow followed by C2. Formic-to-acetic acid (C1/C2) ratios were higher than unity (mean: 1.3 ± 0.3) in the IGP-outflow, whereas they were less than unity (0.9 ± 0.5) in the SEA-outflow. These results suggest that secondary formation of organic acids is largely important in the IGP-outflow whereas primary emission is a major source of organic acids in the SEA-outflow. Based on the correlation coefficient matrix analysis and C1/C2 and C4/C3 ratios, we consider that the sources of C1 are probably associated with the secondary formation via the oxidation of biogenic VOCs, while C2 has both primary and secondary formations associated with anthropogenic sources in the IGP-outflow. On the other hand, C1 and C2 have similar sources (both primary and secondary) originated from biomass burning and bacterial activities via long-range atmospheric transport in the SEA-outflow, as inferred from the MODIS fire spot data, significant concentrations of isovaleric

  16. Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate

    DEFF Research Database (Denmark)

    Jørgensen, Betina; Christiansen, Sofie Egholm; Thomsen, M.L.D.

    2007-01-01

    The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction...... conditions, yields of 90-95% of acetic acid could be achieved at moderate temperatures and pressures. Based on our findings, a reaction pathway for the catalytic oxidation of ethanol via acetaldehyde to acetic acid is proposed, and the rate-determining step (RDS) in the mechanism is found to be the (possibly......, the possibilities for producing ethyl acetate by the aerobic oxidation of ethanol is also studied. At low ethanol concentrations, the main product is acetic acid; at concentrations >60 wt%, it is ethyl acetate....

  17. Crystal structures of four co-crystals of (E)-1,2-di(pyridin-4-yl)ethene with 4-alk-oxy-benzoic acids: 4-meth-oxy-benzoic acid-(E)-1,2-di(pyridin-4-yl)ethene (2/1), 4-eth-oxy-benzoic acid-(E)-1,2-di(pyridin-4-yl)ethene (2/1), 4-n-propoxybenzoic acid-(E)-1,2-di(pyridin-4-yl)ethene (2/1) and 4-n-but-oxy-benzoic acid-(E)-1,2-di(pyridin-4-yl)ethene (2/1).

    Science.gov (United States)

    Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

    2016-11-01

    The crystal structures of four hydrogen-bonded co-crystals of 4-alk-oxy-benzoic acid-(E)-1,2-di(pyridin-4-yl)ethene (2/1), namely, 2C8H8O3·C12H10N2, (I), 2C9H10O3·C12H10N2, (II), 2C10H12O3·C12H10N2, (III) and 2C11H14O3·C12H10N2, (IV), have been determined at 93 K. In compounds (I) and (IV), the asymmetric units are each composed of one 4-alk-oxy-benzoic acid mol-ecule and one half-mol-ecule of (E)-1,2-di(pyridin-4-yl)ethene, which lies on an inversion centre. The asymmetric unit of (II) consists of two crystallographically independent 4-eth-oxy-benzoic acid mol-ecules and one 1,2-di(pyridin-4-yl)ethene mol-ecule. Compound (III) crystallizes in a non-centrosymmetric space group (Pc) and the asymmetric unit comprises four 4-n-propoxybenzoic acid mol-ecules and two (E)-1,2-di(pyridin-4-yl)ethane mol-ecules. In each crystal, the acid and base components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1 unit of the acid and the base. In (I), (II) and (III), inter-molecular C-H⋯O inter-actions are observed. The 2:1 units of (I) and (II) are linked via C-H⋯O hydrogen bonds, forming tape structures. In (III), the C-H⋯O hydrogen bonds, except for those formed in the units, link the two crystallographically independent 2:1 units. In (IV), no C-H⋯O inter-actions are observed, but π-π and C-H⋯π inter-actions link the units into a column structure.

  18. Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.

    Science.gov (United States)

    Forster, Denis; DeKleva, Thomas W.

    1986-01-01

    Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)

  19. Crystal structure of febuxostat–acetic acid (1/1

    Directory of Open Access Journals (Sweden)

    Min Wu

    2015-05-01

    Full Text Available The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-isobutyloxyphenyl-4-methylthiazole-5-carboxylic acid–acetic acid (1/1], C16H16N2O3S·CH3COOH, contains a febuxostat molecule and an acetic acid molecule. In the febuxostat molecule, the thiazole ring is nearly coplanar with the benzene ring [dihedral angle = 3.24 (2°]. In the crystal, the febuxostat and acetic acid molecules are linked by O—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds, forming supramolecular chains propagating along the b-axis direction. π–π stacking is observed between nearly parallel thiazole and benzene rings of adjacent molecules; the centroid-to-centroid distances are 3.8064 (17 and 3.9296 (17 Å.

  20. Catabolism of indole-3-acetic acid and 4- and 5-chloroindole-3-acetic acid in Bradyrhizobium japonicum

    DEFF Research Database (Denmark)

    Jensen, J B; Egsgaard, H; Van Onckelen, H

    1995-01-01

    Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid chromatogr...

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

    Science.gov (United States)

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

    2011-06-01

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

  2. Catabolism of indole-3-acetic acid and 4- and 5-chloroindole-3-acetic acid in Bradyrhizobium japonicum

    DEFF Research Database (Denmark)

    Jensen, J B; Egsgaard, H; Van Onckelen, H

    1995-01-01

    Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid...... chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic pathway in which IAA is metabolized via dioxindole-3-acetic acid, dioxindole, isatin, and 2......-aminophenyl glyoxylic acid (isatinic acid) to anthranilic acid, which is further metabolized. Degradation of 4-Cl-IAA apparently stops at the 4-Cl-dioxindole step in contrast to 5-Cl-IAA which is metabolized to 5-Cl-anthranilic acid. Udgivelsesdato: 1995-Oct...

  3. Hydrogen bonding and liquid crystallinity of low molar mass and polymeric mesogens containing benzoic acids: a variable temperature Fourier transform infrared spectroscopic study

    Science.gov (United States)

    Martínez-Felipe, A.; Cook, A. G.; Wallage, M. J.; Imrie, C. T.

    2014-12-01

    The phase behaviour and mesomorphism of poly(4-(6-propenoyloxyhexyloxy)benzoic acid) (PPOHBA) and 4-pentyloxybenzoic acid (POBA) is studied using variable-temperature Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction. PPHOBA exhibits a smectic C phase and POBA, a nematic phase. The temperature dependence of the Fermi resonance bands associated with the hydroxyl groups and of the carbonyl stretching region in the FTIR spectra indicates that there is a dynamic equilibrium between monomers and open and closed dimers formed by hydrogen bonding between benzoic acid moieties. The nematic phase observed for POBA is linked to the anisotropic cyclic dimer, while an abrupt increase in the concentration of monomer drives isotropisation. In PPOHBA, hydrogen-bonded supramesogens promote smectic behaviour, while hydrogen-bonded crosslinks stabilise the lamellae. The increased viscosity arising from this dynamic crosslinking is offset by the flexibility of the acrylate backbone and alkyl spacers.

  4. Summer and winter variations of dicarboxylic acids, fatty acids and benzoic acid in PM2.5 in Pearl Delta River Region, China

    Directory of Open Access Journals (Sweden)

    K. Kawamura

    2010-11-01

    Full Text Available Ground-based PM2.5 samples collected in Pearl River Delta (PRD region during winter and summer (from 14 December 2006 to 28 January 2007 in winter and from 4 July 2007 to 9 August 2007 in summer were analyzed for 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C2 was the most abundant species followed by phthalic acid (Ph in PRD region. The concentrations of total dicarboxylic acids ranged from 99 to 1340 ng m−3, with an average of 438 ± 267 ng m−3 in PRD. The concentrations of total ketocarboxylic acids ranged from 0.6 to 207 ng m−3 (43 ± 48 ng m−3 on average while the concentrations of total α-dicarbonyls, including glyoxal and methylglyoxal, ranged from 0.2 to 89 ng m−3, with an average of 11 ± 18 ng m−3 in PRD. The total quantified water-soluble organic carbon (TQWOC accounted for 3.4 ± 2.2% of OC and 14.3 ± 10.3% of water-soluble OC (WSOC. Hexadecanoic acid (C16:0, octadecanoic acid (C18:0 and oleic acid (C18:1 are the three most abundant fatty acids in PRD. The distributions of fatty acids are characterized by a strong even carbon number predominance with a maximum (Cmax at hexadecanoic acid (C16:0. Ratio of C18:1 to C18:0 acts as an indicator for aerosol aging. In PRD, an average of C18:1/C18:0 ratio was 0.53 ± 0.39, suggesting an enhanced photochemical degradation of unsaturated fatty acid. Seasonal variations of the pollutant concentrations were found in the four sampling cities. Higher concentrations of TQWOC were observed in winter (544 ng m−3 than in summer (318 ng m−3. However, the abundances of TQWOC in OC mass were higher in summer (1.8–12.4%, 5.4% on average than in winter (1.1–5.7, 2.6% on average, being consistent with enhanced secondary production of dicarboxylic acids in warmer weather. Spatial variations of water-soluble dicarboxylic

  5. Catalytic Esterification of Methyl Alcohol with Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Esterification of methyl alcohol with acetic acid catalysed by Amberlyst-15 (cation-exchange resin) was carried out in a batch reactor in the temperature ranging between 318-338 K, at atmospheric pressure. The reaction rate increased with increase in catalyst concentration and reaction temperature, but decreased with an increase in water concentration. Stirrer speed had virtually no effect on the rate under the experimental conditions. The rate data were correlated with a second-order kinetic model based on homogeneous reaction. The apparent activation energy was found to be 22.9kJ.mo1-1 for the formation of methyl acetate. The methyl acetate production was carried out aa batch and continuous in a packed bed restive distillation column with high purity methyl acetate produced.

  6. Theoretical investigations on the structure and properties of p-n-alkoxy benzoic acid based liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Subhapriya, P., E-mail: subhapriyachem@gmail.com; Dhanapal, V.; Sadasivam, K.; Vijayanand, P. S. [Department of Physical sciences, Bannari Amman Institute of Technology (Autonomous), Sathyamangalam, Erode-638 401, Tamil Nadu (India)

    2016-05-06

    The present study focused on the structural conformations, alkoxy chain lengths and mesogenic properties of two mole of alkoxy benzoic acid(nOBA) and one mole of suberic acid (SA) hydrogen bonded (nOBASA) complexes (n=8 to 10) by density functional theory (DFT) calculations and the Fourier Transform Infrared (FT-IR) spectrum. The intermolecular hydrogen bond formation was confirmed by the optimized geometric bond lengths and bond angles obtained by computation. Using the natural bond orbital (NBO) analysis, the stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed. Results obtained shows that the charge in electron density (ED) in σ*and π* antibonding orbital and second order delocalization energies E(2) authorizes the occurrence of intermolecular charge transfer. The molecular electrostatic potential (MEP) surface map is plotted over the optimized geometry of the molecule to obtain the chemical reactivity of the molecule. From the local charge distributions, the mesomorphic behavior and the nematic phase stabilities for each of the molecule have been predicted. Finally the calculated result is applied to simulated infrared spectra of 8OBASA mesogens which shows good agreement with the observed spectra. The comparison of the theoretical results obtained with the experimental ones shows the reliability of this DFT method.

  7. The structure of the complex between avidin and the dye, 2-(4'-hydroxyazobenzene) benzoic acid (HABA).

    Science.gov (United States)

    Livnah, O; Bayer, E A; Wilchek, M; Sussman, J L

    1993-08-09

    The crystal structure of the complex formed between the egg-white biotin-binding protein, avidin, and the dye, 2-(4'-hydroxyazobenzene) benzoic acid (HABA), was determined to a resolution of 2.5 A. The interaction of avidin with the benzoate ring of HABA is essentially identical to that of the complex formed between HABA and streptavidin (the bacterial analogue of the egg-white protein). This interaction emulates the definitive high-affinity interaction of both proteins with the ureido moiety of biotin. The major difference between the avidin- and streptavidin-HABA complexes lies in their interaction with the hydroxyphenyl ring of the dye molecule; in avidin, two adjacent amino acid residues (Phe72 and Ser73), which are not present in streptavidin, form additional interactions with this ring. These are suggested to account for the higher affinity of avidin for HABA. The characteristic red shift, which accompanies the interaction of both proteins with the dye, was traced to a proposed charge-transfer complex formed between the hydroxyphenyl ring of HABA and the indole ring of Trp70 in avidin (Trp79 in streptavidin). Comparison of binding site residues of two such similar proteins versus their markedly different affinities for two such different substrates should eventually contribute to a better design of biomimetic reagents and drugs.

  8. Iron Oxide Surface Chemistry: The Effect of Chemical Structure on Binding in Benzoic Acid and Catechol Derivatives.

    Science.gov (United States)

    Korpany, Katalin V; Majewski, Dorothy D; Chiu, Cindy T; Cross, Shoronia N; Blum, Amy Szuchmacher

    2017-02-18

    Excellent performance of functionalized iron oxide nanoparticles in nanomaterial and biomedical applications often relies on achieving attachment of ligands to the iron oxide surface both in sufficient number and with proper orientation. Towards this end, we determine relationships between ligand chemical structure and surface binding on magnetic iron oxide nanoparticles for a series of related benzoic acid and catechol derivatives. Ligand exchange was used to introduce the model ligands, and the resulting nanoparticles were characterized by FTIR-ATR, transmission electron microscopy (TEM), and nanoparticle solubility behavior. An in-depth analysis of ligand electronic effects and reaction conditions reveals that the nature of ligand binding does not solely depend on the presence of functional groups known to bind to iron oxide nanoparticles. The structure of the resulting ligand-surface complex was primarily influenced by the relative positioning of hydroxyl and carboxylic acid groups within the ligand as well as whether or not HCl(aq) was added to the ligand exchange reaction. Overall, this study will help guide future ligand design and ligand exchange strategies towards realizing truly custom-built iron oxide nanoparticles.

  9. Growth, thermal, dielectric and mechanical properties of L-phenylalanine-benzoic acid: A nonlinear optical single crystal

    Science.gov (United States)

    Tamilselvan, S.; Vimalan, M.; Vetha Potheher, I.; Rajasekar, S.; Jeyasekaran, R.; Antony Arockiaraj, M.; Madhavan, J.

    2013-10-01

    An efficient amino acid family nonlinear optical single crystal L-phenylalanine-benzoic acid (LPB) was conveniently grown by slow evaporation technique at room temperature. The crystal system and the lattice parameters were analyzed by single crystal X-ray diffraction studies. The grown crystal has excellent transmission in the entire visible region and its lower cut-off wavelength was found to be 248 nm. The SHG efficiency of the grown crystal was found to be 1.6 times higher than that of KDP crystal. The Laser damage threshold value of LPB has been found to be 6.5 GW/cm2. The sample was thermally stable up to 134 °C. Microhardness, dielectric and AC/DC conductivity measurements were made along (0 0 1) plane and reported for the first time. Microhardness studies revealed that the sample belongs to hard nature. Frequency dependent dielectric constant was measured for different temperatures and found maximum dielectric constant of 14 for 363 K. Photoconductivity studies of LPB divulged its negative photoconducting nature.

  10. Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum

    Energy Technology Data Exchange (ETDEWEB)

    Shah, M.M.; Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31

    Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.

  11. Highly Concentrated Acetic Acid Poisoning: 400 Cases Reviewed

    Directory of Open Access Journals (Sweden)

    Konstantin Brusin

    2012-12-01

    Full Text Available Background: Caustic substance ingestion is known for causing a wide array of gastrointestinal and systemic complications. In Russia, ingestion of acetic acid is a major problem which annually affects 11.2 per 100,000 individuals. The objective of this study was to report and analyze main complications and outcomes of patients with 70% concentrated acetic acid poisoning. Methods: This was a retrospective study of patients with acetic acid ingestion who were treated at Sverdlovsk Regional Poisoning Treatment Center during 2006 to 2012. GI mucosal injury of each patient was assessed with endoscopy according to Zargar’s scale. Data analysis was performed to analyze the predictors of stricture formation and mortality. Results: A total of 400 patients with median age of 47 yr were included. GI injury grade I was found in 66 cases (16.5%, IIa in 117 (29.3%, IIb in 120 (30%, IIIa in 27 (16.7% and IIIb in 70 (17.5%. 11% of patients developed strictures and overall mortality rate was 21%. Main complications were hemolysis (55%, renal injury (35%, pneumonia (27% and bleeding during the first 3 days (27%. Predictors of mortality were age 60 to 79 years, grade IIIa and IIIb of GI injury, pneumonia, stages “I”, “F” and “L” of kidney damage according to the RIFLE scale and administration of prednisolone. Predictors of stricture formation were ingestion of over 100 mL of acetic acid and grade IIb and IIIa of GI injury. Conclusion: Highly concentrated acetic acid is still frequently ingested in Russia with a high mortality rate. Patients with higher grades of GI injury, pneumonia, renal injury and higher amount of acid ingested should be more carefully monitored as they are more susceptible to develop fatal consequences.          

  12. First Acetic Acid Survey with CARMA in Hot Molecular Cores

    CERN Document Server

    Shiao, Y -S Jerry; Remijan, Anthony J; Snyder, Lewis E; Friedel, Douglas N

    2010-01-01

    Acetic acid (CH$_3$COOH) has been detected mainly in hot molecular cores where the distribution between oxygen (O) and nitrogen (N) containing molecular species is co-spatial within the telescope beam. Previous work has presumed that similar cores with co-spatial O and N species may be an indicator for detecting acetic acid. However, does this presumption hold as higher spatial resolution observations become available of large O and N-containing molecules? As the number of detected acetic acid sources is still low, more observations are needed to support this postulate. In this paper, we report the first acetic acid survey conducted with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at 3 mm wavelengths towards G19.61-0.23, G29.96-0.02 and IRAS 16293-2422. We have successfully detected CH$_3$COOH via two transitions toward G19.61-0.23 and tentatively confirmed the detection toward IRAS 16293-2422 A. The determined column density of CH$_3$COOH is 2.0(1.0)$\\times 10^{16}$ cm$^{-2}$ and the...

  13. Intramolecular carbon isotope distribution of acetic acid in vinegar.

    Science.gov (United States)

    Hattori, Ryota; Yamada, Keita; Kikuchi, Makiko; Hirano, Satoshi; Yoshida, Naohiro

    2011-09-14

    Compound-specific carbon isotope analysis of acetic acid is useful for origin discrimination and quality control of vinegar. Intramolecular carbon isotope distributions, which are each carbon isotope ratios of the methyl and carboxyl carbons in the acetic acid molecule, may be required to obtain more detailed information to discriminate such origin. In this study, improved gas chromatography-pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (GC-Py-GC-C-IRMS) combined with headspace solid-phase microextraction (HS-SPME) was used to measure the intramolecular carbon isotope distributions of acetic acid in 14 Japanese vinegars. The results demonstrated that the methyl carbons of acetic acid molecules in vinegars produced from plants were mostly isotopically depleted in (13)C relative to the carboxyl carbon. Moreover, isotopic differences (δ(13)C(carboxyl) - δ(13)C(methyl)) had a wide range from -0.3 to 18.2‰, and these values differed among botanical origins, C3, C4, and CAM plants.

  14. Fries Rearrangement of Phenyl Acetate over Solid Acid Catalyst

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.

  15. Fries Rearrangement of Phenyl Acetate over Solid Acid Catalyst

    Institute of Scientific and Technical Information of China (English)

    CanXiongGUO; YanLIU; 等

    2002-01-01

    A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD,IR,XPS,pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.

  16. Highly selective and effective solid phase microextraction of benzoic acid esters using ionic liquid functionalized multiwalled carbon nanotubes-doped polyaniline coating.

    Science.gov (United States)

    Ai, Youhong; Wu, Mian; Li, Lulu; Zhao, Faqiong; Zeng, Baizhao

    2016-03-11

    The present work reports the electrochemical fabrication of an ionic liquid functionalized multiwalled carbon nanotubes-polyaniline (MWCNT@IL/PANI) nanocomposite coating and its application in the headspace-solid phase microextraction (HS-SPME) and gas chromatography (GC) determination of benzoic acid esters (i.e., methyl benzoate, ethyl benzoate, propyl benzoate and butyl benzoate). The MWCNTs was firstly functionalized with amine-terminated IL (MWCNT@IL) through chemical reduction, and then was doped in PANI during the electropolymerization of aniline. The resulting coating was characterized by infrared spectroscopy, field emission scanning electron microscopy and thermo gravimetry. It showed net-like structure and had high thermal stability (up to 330°C). Furthermore, it presented high selectivity for the four benzoic acid esters and thus suited for their HS-SPME-GC determination. Results showed that under optimized extraction conditions, the detection limits were less than 6.1ngL(-1) (S/N=3) and the linear detection ranges were 0.012-50μgL(-1) (R≥0.9957) for these analytes. The relative standard deviations (RSDs) were lower than 6.4% for five successive measurements with one fiber, and the RSDs for fiber-to-fiber were 4.4-9.6% (n=5). The developed method was successfully applied to the determination of these benzoic acid esters in perfume samples.

  17. Ligand sensitized luminescence of uranyl by benzoic acid in acetonitrile medium: a new luminescent uranyl benzoate specie.

    Science.gov (United States)

    Kumar, Satendra; Maji, S; Joseph, M; Sankaran, K

    2015-03-05

    Benzoic acid (BA) is shown to sensitize and enhance the luminescence of uranyl ion in acetonitrile medium. Luminescence spectra and especially UV-Vis spectroscopy studies reveal the formation of tri benzoate complex of uranyl i.e. [UO2(C6H5COO)3](-) which is highly luminescent. In particular, three sharp bands at 431, 443, 461nm of absorption spectra provides evidence for tri benzoate specie of uranyl in acetonitrile medium. The luminescence lifetime of uranyl in this complex is 68μs which is much more compared to the lifetime of uncomplexed uranyl (20μs) in acetonitrile medium. In contrary to aqueous medium where uranyl benzoate forms 1:1 and 1:2 species, spectroscopic data reveal formation of 1:3 complex in acetonitrile medium. Addition of water to acetonitrile results in decrease of luminescence intensity of this specie and the luminescence features implode at 20% (v/v) of water content. For the first time, to the best of our knowledge, the existence of [UO2(C6H5COO)3](-) specie in acetonitrile is reported. Mechanism of luminescence enhancement is discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. New Polyketides and New Benzoic Acid Derivatives from the Marine Sponge-Associated Fungus Neosartorya quadricincta KUFA 0081

    Science.gov (United States)

    Prompanya, Chadaporn; Dethoup, Tida; Gales, Luís; Lee, Michael; Pereira, José A. C.; Silva, Artur M. S.; Pinto, Madalena M. M.; Kijjoa, Anake

    2016-01-01

    Two new pentaketides, including a new benzofuran-1-one derivative (1) and a new isochromen-1-one (5), and seven new benzoic acid derivatives, including two new benzopyran derivatives (2a, b), a new benzoxepine derivative (3), two new chromen-4-one derivatives (4b, 7) and two new benzofuran derivatives (6a, b), were isolated, together with the previously reported 2,3-dihydro-6-hydroxy-2,2-dimethyl-4H-1-benzopyran-4-one (4a), from the culture of the marine sponge-associated fungus Neosartorya quadricincta KUFA 0081. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis, and in the case of compounds 1, 2a, 4b, 5, 6a and 7, the absolute configurations of their stereogenic carbons were determined by an X-ray crystallographic analysis. None of the isolated compounds were active in the tests for antibacterial activity against Gram-positive and Gram-negative bacteria, as well as multidrug-resistant isolates from the environment (MIC > 256 μg/mL), antifungal activity against yeast (Candida albicans ATTC 10231), filamentous fungus (Aspergillus fumigatus ATTC 46645) and dermatophyte (Trichophyton rubrum FF5) (MIC > 512 µg/mL) and in vitro growth inhibitory activity against the MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and A375-C5 (melanoma) cell lines (GI50 > 150 µM) by the protein binding dye SRB method. PMID:27438842

  19. New Polyketides and New Benzoic Acid Derivatives from the Marine Sponge-Associated Fungus Neosartorya quadricincta KUFA 0081

    Directory of Open Access Journals (Sweden)

    Chadaporn Prompanya

    2016-07-01

    Full Text Available Two new pentaketides, including a new benzofuran-1-one derivative (1 and a new isochromen-1-one (5, and seven new benzoic acid derivatives, including two new benzopyran derivatives (2a, b, a new benzoxepine derivative (3, two new chromen-4-one derivatives (4b, 7 and two new benzofuran derivatives (6a, b, were isolated, together with the previously reported 2,3-dihydro-6-hydroxy-2,2-dimethyl-4H-1-benzopyran-4-one (4a, from the culture of the marine sponge-associated fungus Neosartorya quadricincta KUFA 0081. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis, and in the case of compounds 1, 2a, 4b, 5, 6a and 7, the absolute configurations of their stereogenic carbons were determined by an X-ray crystallographic analysis. None of the isolated compounds were active in the tests for antibacterial activity against Gram-positive and Gram-negative bacteria, as well as multidrug-resistant isolates from the environment (MIC > 256 μg/mL, antifungal activity against yeast (Candida albicans ATTC 10231, filamentous fungus (Aspergillus fumigatus ATTC 46645 and dermatophyte (Trichophyton rubrum FF5 (MIC > 512 µg/mL and in vitro growth inhibitory activity against the MCF-7 (breast adenocarcinoma, NCI-H460 (non-small cell lung cancer and A375-C5 (melanoma cell lines (GI50 > 150 µM by the protein binding dye SRB method.

  20. Ligand sensitized luminescence of uranyl by benzoic acid in acetonitrile medium: A new luminescent uranyl benzoate specie

    Science.gov (United States)

    Kumar, Satendra; Maji, S.; Joseph, M.; Sankaran, K.

    2015-03-01

    Benzoic acid (BA) is shown to sensitize and enhance the luminescence of uranyl ion in acetonitrile medium. Luminescence spectra and especially UV-Vis spectroscopy studies reveal the formation of tri benzoate complex of uranyl i.e. [UO2(C6H5COO)3]- which is highly luminescent. In particular, three sharp bands at 431, 443, 461 nm of absorption spectra provides evidence for tri benzoate specie of uranyl in acetonitrile medium. The luminescence lifetime of uranyl in this complex is 68 μs which is much more compared to the lifetime of uncomplexed uranyl (20 μs) in acetonitrile medium. In contrary to aqueous medium where uranyl benzoate forms 1:1 and 1:2 species, spectroscopic data reveal formation of 1:3 complex in acetonitrile medium. Addition of water to acetonitrile results in decrease of luminescence intensity of this specie and the luminescence features implode at 20% (v/v) of water content. For the first time, to the best of our knowledge, the existence of [UO2(C6H5COO)3]- specie in acetonitrile is reported. Mechanism of luminescence enhancement is discussed.

  1. Study of cross - relaxation and molecular dynamics in the solid 3-(trifluoromethyl) benzoic acid by solid state NMR off - resonance.

    Science.gov (United States)

    Woźniak-Braszak, Aneta

    2017-02-01

    Molecular dynamics of the solid 3-(trifluoromethyl) benzoic acid containing proton (1)H and fluorine (19)F nuclei was explored by the solid-state NMR off - resonance technique. Contrary to the previous experiments the proton nuclei system I relaxed in the off - resonance effective field B→e while fluorine nuclei system S was saturated for short time in comparison to the relaxation time T1I. New cross - relaxation solid - state NMR off - resonance experiments were conducted on a homebuilt pulse spectrometer operating at the on-resonance frequency of 30.2MHz, at the off - resonance frequency varied between 30.2 and 30.6MHz for protons and at the frequency of 28.411MHz for fluorines, respectively. Based on the experimental data the dispersions of the proton off - resonance spin - lattice relaxation rate ρρ(I), the fluorine off - resonance spin - lattice relaxation rate ρρ(S) and the cross - relaxation rate σρ in the rotating frame were determined. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays

    Science.gov (United States)

    Lewer, P.; Bandurski, R. S.

    1987-01-01

    7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

  3. Antimicrobial activity of rhodanine-3-acetic acid derivatives.

    Science.gov (United States)

    Krátký, Martin; Vinšová, Jarmila; Stolaříková, Jiřina

    2017-03-15

    Twenty-four 2-(4-oxo-2-thioxothiazolidin-3-yl)acetic acid (rhodanine-3-acetic acid)-based amides, esters and 5-arylalkylidene derivatives were synthesized, characterized and evaluated as potential antimicrobial agents against a panel of bacteria, mycobacteria and fungi. All of the derivatives were active against mycobacteria. N-(4-Chlorophenyl)-2-[5-(2-hydroxybenzylidene)-4-oxo-2-thioxothiazolidin-3-yl]acetamide demonstrated the highest activity against Mycobacterium tuberculosis with minimum inhibitory concentrations (MIC) of 8-16μM. Non-tuberculous mycobacteria were the most susceptible to 2-[5-(2-hydroxybenzylidene)-4-oxo-2-thioxothiazolidin-3-yl]acetic acids (MIC values ⩾32μM). The highest antibacterial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus exhibited 4-(trifluoromethyl)phenyl 2-(4-oxo-2-thioxothiazolidin-3-yl)acetate (MIC⩾15.62μM). Several structure-activity relationships were identified. The activity against Gram-negative and fungal pathogens was marginal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

    Science.gov (United States)

    Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-02-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation.

  5. Age-dependent changes from allylphenol to prenylated benzoic acid production in Piper gaudichaudianum Kunth.

    Science.gov (United States)

    Gaia, Anderson M; Yamaguchi, Lydia F; Jeffrey, Christopher S; Kato, Massuo J

    2014-10-01

    HPLC-DAD and principal component analysis (PCA) of the (1)H NMR spectrum of crude plant extracts showed high chemical variability among seedlings and adult organs of Piper gaudichaudianum. While gaudichaudianic acid was the major compound in the adult leaves, apiole and dillapiole were the major compounds in their seedling leaves. By the 15th month of seedling growth, the levels of apiole and dillapiole decreased and gaudichaudianic acid appeared along with two compounds, biosynthetically related to gaudichaudianic acid.

  6. A continuous acetic acid system for polyacrylamide gel electrophoresis of gliadins and other prolamines.

    Science.gov (United States)

    Clements, R L

    1988-02-01

    A polyacrylamide gel electrophoresis system buffered by acetic acid alone was developed for electrophoresis of prolamines. When applied to gliadin electrophoresis, the acetic acid system produces more bands than does a conventional aluminum lactate-lactic acid system (using 12% acrylamide gels). The acetic acid system is relatively simple, requiring a single buffer component that is universally available in high purity.

  7. [Conversion of acetic acid to methane by thermophiles: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Zinder, S.

    1991-12-31

    The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

  8. (Conversion of acetic acid to methane by thermophiles: Progress report)

    Energy Technology Data Exchange (ETDEWEB)

    Zinder, S.

    1991-01-01

    The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

  9. Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system

    Directory of Open Access Journals (Sweden)

    E. Ince

    2002-04-01

    Full Text Available Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  10. Novel class of benzoic acid ester derivatives as potent PDE4 inhibitors for inhaled administration in the treatment of respiratory diseases.

    Science.gov (United States)

    Armani, Elisabetta; Amari, Gabriele; Rizzi, Andrea; De Fanti, Renato; Ghidini, Eleonora; Capaldi, Carmelida; Carzaniga, Laura; Caruso, Paola; Guala, Matilde; Peretto, Ilaria; La Porta, Elena; Bolzoni, Pier T; Facchinetti, Fabrizio; Carnini, Chiara; Moretto, Nadia; Patacchini, Riccardo; Bassani, Franco; Cenacchi, Valentina; Volta, Roberta; Amadei, Francesco; Capacchi, Silvia; Delcanale, Maurizio; Puccini, Paola; Catinella, Silvia; Civelli, Maurizio; Villetti, Gino

    2014-02-13

    The first steps in the selection process of a new anti-inflammatory drug for the inhaled treatment of asthma and chronic obstructive pulmonary disease are herein described. A series of novel ester derivatives of 1-(3-(cyclopropylmethoxy)-4-(difluoromethoxy)phenyl)-2-(3,5-dichloropyridin-4-yl) ethanol have been synthesized and evaluated for inhibitory activity toward cAMP-specific phosphodiesterase-4 (PDE4). In particular, esters of variously substituted benzoic acids were extensively explored, and structural modification of the alcoholic and benzoic moieties were performed to maximize the inhibitory potency. Several compounds with high activity in cell-free and cell-based assays were obtained. Through the evaluation of opportune in vitro ADME properties, a potential candidate suitable for inhaled administration in respiratory diseases was identified and tested in an in vivo model of pulmonary inflammation, proving its efficacy.

  11. Collision-induced dissociation processes of protonated benzoic acid and related compounds: competitive generation of protonated carbon dioxide or protonated benzene.

    Science.gov (United States)

    Xu, Sihang; Pavlov, Julius; Attygalle, Athula B

    2017-04-01

    Upon activation in the gas phase, protonated benzoic acid (m/z 123) undergoes fragmentation by several mechanisms. In addition to the predictable water loss followed by a CO loss, the m/z 123 ion more intriguingly eliminates a molecule of benzene to generate protonated carbon dioxide (H - O(+)  ═ C ≡ O, m/z 45), or a molecule of carbon dioxide to yield protonated benzene (m/z 79). Experimental evidence shows that the incipient proton ambulates during the fragmentation processes. For the CO2 or benzene loss, protonated benzoic acid transfers the charge-imparting proton initially to the ortho position and then to the ipso position to generate a transient species which dissociates to form an ion-neutral complex between benzene and protonated CO2 . The formation of the m/z 45 ion is not a phenomenon unique to benzoic acid: spectra from protonated isophthalic acid, terephthalic acid, trans-cinnamic acid and some aliphatic acids also displayed a peak for m/z 45. However, the m/z 45 peak is structurally diagnostic only for certain benzene polycarboxylic acids because the spectra of compounds with two carboxyl groups on adjacent ring carbons do not produce a peak at m/z 45. For the m/z 79 ion to be formed, an intramolecular reaction should take place in which protonated CO2 within the ion-neutral complex acts as the attacking electrophile to transfer a proton to benzene. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Evaporation kinetics of acetic acid-water solutions

    Science.gov (United States)

    Duffey, K.; Wong, N.; Saykally, R.; Cohen, R. C.

    2012-12-01

    The transport of water molecules across vapor-liquid interfaces in the atmosphere is a crucial step in the formation and evolution of cloud droplets. Despite decades of study, the effects of solutes on the mechanism and rate of evaporation and condensation remain poorly characterized. The present work aims to determine the effect of atmospherically-relevant solutes on the evaporation rate of water. In our experiments, we create a train of micron-sized droplets and measure their temperature via Raman thermometry as they undergo evaporation without condensation. Analysis of the cooling rate yields the evaporation coefficient (γ). Previous work has shown that inorganic salts have little effect on γ, with surface-adsorbing anions causing a slight reduction in the coefficient from that measured for pure water. Organic acids are ubiquitous in aqueous aerosol and have been shown to disrupt the surface structure of water. Here we describe measurements of the evaporation rate of acetic acid solutions, showing that acetic acid reduces γ to a larger extent than inorganic ions, and that γ decreases with increasing acetic acid concentration.

  13. Acetic acid pretreatment improves the hardness of cooked potato slices.

    Science.gov (United States)

    Zhao, Wenlin; Shehzad, Hussain; Yan, Shoulei; Li, Jie; Wang, Qingzhang

    2017-08-01

    The effects of acetic acid pretreatment on the texture of cooked potato slices were investigated in this work. Potato slices were pretreated with acetic acid immersion (AAI), distilled water immersion (DWI), or no immersion (NI). Subsequently, the cell wall material of the pretreated samples was isolated and fractioned to evaluate changes in the monosaccharide content and molar mass (MM), and the hardness and microscopic structure of the potato slices in different pretreatments before and after cooking were determined. The results showed that the highest firmness was obtained with more intact structure of the cell wall for cooked potato slices with AAI pretreatment. Furthermore, the MM and sugar ratio demonstrated that the AAI pretreated potato slices contained a higher content of the small molecular polysaccharides of cell walls, especially in the hemicellulose fraction. This work may provide a reference for potato processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System

    OpenAIRE

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

  15. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods

    OpenAIRE

    Sharafi, SM; I Rasooli; K Beheshti-Maal

    2010-01-01

    Background and Objectives Acetic acid bacteria (AAB) are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity. Materials and Methods Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC) medium. Carr medium supplemented with bromocresol green was used for distingui...

  16. Acetic acid enhances endurance capacity of exercise-trained mice by increasing skeletal muscle oxidative properties.

    Science.gov (United States)

    Pan, Jeong Hoon; Kim, Jun Ho; Kim, Hyung Min; Lee, Eui Seop; Shin, Dong-Hoon; Kim, Seongpil; Shin, Minkyeong; Kim, Sang Ho; Lee, Jin Hyup; Kim, Young Jun

    2015-01-01

    Acetic acid has been shown to promote glycogen replenishment in skeletal muscle during exercise training. In this study, we investigated the effects of acetic acid on endurance capacity and muscle oxidative metabolism in the exercise training using in vivo mice model. In exercised mice, acetic acid induced a significant increase in endurance capacity accompanying a reduction in visceral adipose depots. Serum levels of non-esterified fatty acid and urea nitrogen were significantly lower in acetic acid-fed mice in the exercised mice. Importantly, in the mice, acetic acid significantly increased the muscle expression of key enzymes involved in fatty acid oxidation and glycolytic-to-oxidative fiber-type transformation. Taken together, these findings suggest that acetic acid improves endurance exercise capacity by promoting muscle oxidative properties, in part through the AMPK-mediated fatty acid oxidation and provide an important basis for the application of acetic acid as a major component of novel ergogenic aids.

  17. Microwave Irradiation Promoted Synthesis of Aryloxy Acetic Acids

    Institute of Scientific and Technical Information of China (English)

    LIN Min; ZHOU Jin-mei; XIA Hai-ping; YANG Rui-feng; LIN Chen

    2004-01-01

    Several aryloxy acetic acids were synthesized under microwave irradiation. The factors, which affect the reaction, were investigated and optimized. It was revealed that the best yields(92.7%-97.4%) were obtained when the molar ratio of the reactants was n(ArOH) : n(NaOH): n(ClCH2CO2H) =1: 2.5: 1.2 with microwave irradiation power of 640 W for 65-85 s.

  18. Kinetics of xylose dehydration into furfural in acetic acid

    Institute of Scientific and Technical Information of China (English)

    Zhou Chen; Weijiang Zhang; Jiao Xu; Pingli Li

    2015-01-01

    In this paper kinetics of xylose dehydration into furfural using acetic acid as catalyst was studied comprehensively and systematical y. The reaction order of both furfural and xylose dehydration was determined and the reaction activation energy was obtalned by nonlinear regression. The effect of acetic acid concentration was also investi-gated. Reaction rate constants were galned. Reaction rate constant of xylose dehydration is k1 ¼ 4:189 . 1010 ½A.0:1676 exp −108:6.1000RT . ., reaction rate constant of furfural degradation is k2 ¼ 1:271 . 104½A.0:1375 exp−63:413.1000RT . and reaction rate constant of condensation reaction is k3 ¼ 3:4051 . 1010½A.0:1676 exp−104:99.1000RT .. Based on this, the kinetics equation of xylose dehydration into furfural in acetic acid was set up according to theory of Dunlop and Furfural generating rate equation is dd½F.t ¼ k1½X.0e−k1t−k2½F.−k3½X.0e−k1t½F.. © 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  19. 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...

  20. 40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acetic acid; exemption from the... Exemptions From Tolerances § 180.1258 Acetic acid; exemption from the requirement of a tolerance. An... acetic acid when used as a preservative on post-harvest agricultural commodities intended for animal...

  1. 21 CFR 175.350 - Vinyl acetate/crotonic acid copolymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl acetate/crotonic acid copolymer. 175.350... COATINGS Substances for Use as Components of Coatings § 175.350 Vinyl acetate/crotonic acid copolymer. A copolymer of vinyl acetate and crotonic acid may be safely used as a coating or as a component of a...

  2. 2-{[1-(3,4-Dihydroxyphenyl)methylidene]amino}benzoic acid immobilized Amberlite XAD-16 as metal extractant.

    Science.gov (United States)

    Venkatesh, Gopalan; Singh, Ajai K

    2005-07-15

    2-{[1-(3,4-Dihydroxyphenyl)methylidene]amino}benzoic acid (DMABA) was loaded on Amberlite XAD-16 (AXAD-16) via azo linker and the resulting resin AXAD-16-DMABA explored for enrichment of Zn(II), Mn(II), Ni(II), Pb(II), Cd(II), Cu(II), Fe(III) and Co(II). The optimum pH values for extraction are 6.5-7.0, 5.0-6.0, 5.5-7.5, 5.0-6.5, 6.5-8.0, 5.5-7.0, 4.0-5.0 and 6.0-7.0, respectively. The sorption capacity was found between 97 and 515mumolg(-1) and the preconcentration factors from 100 to 450. Tolerance limits for foreign species are reported. The kinetics of sorption is fast as t(1/2) is

  3. Acetic Acid bacteria: physiology and carbon sources oxidation.

    Science.gov (United States)

    Mamlouk, Dhouha; Gullo, Maria

    2013-12-01

    Acetic acid bacteria (AAB) are obligately aerobic bacteria within the family Acetobacteraceae, widespread in sugary, acidic and alcoholic niches. They are known for their ability to partially oxidise a variety of carbohydrates and to release the corresponding metabolites (aldehydes, ketones and organic acids) into the media. Since a long time they are used to perform specific oxidation reactions through processes called "oxidative fermentations", especially in vinegar production. In the last decades physiology of AAB have been widely studied because of their role in food production, where they act as beneficial or spoiling organisms, and in biotechnological industry, where their oxidation machinery is exploited to produce a number of compounds such as l-ascorbic acid, dihydroxyacetone, gluconic acid and cellulose. The present review aims to provide an overview of AAB physiology focusing carbon sources oxidation and main products of their metabolism.

  4. Analysis of benzoic and cinnamic acid derivatives of some medicinal plants in Serbia

    Directory of Open Access Journals (Sweden)

    Đurđević L.

    2013-01-01

    Full Text Available Natural phenolics, which are ubiquitously distributed in plants, have been reported as functional factors in phytotherapy. We have examined phenolic compounds in the leaves and inflorescences of five significant medicinal plants of different plant families: Salvia officinalis (Lamiaceae; Achillea clypeolata (Asteraceae; Nymphaea alba (Nymphaeaceae; Rumex acetosella (Polygonaceae and Allium ursinum (Alliaceae. The examined species were rich in total phenolics (up to 30.88 mg/g dry weight. According to their total phenolics contents, the plants can be arranged in the following order: A. clypeolata>N. alba>S. officinalis>R. acetosella>A. ursinum. Free phenolics prevailed in all species in comparison to the bound forms (63.72-82.68% of total phenolics. The highest content of total free phenolics was measured in the tissues of A. clypeolata and N. alba, and the lowest in A. ursinum. Five phenolic acids were isolated and measured. p-Coumaric and ferulic acids as derivatives of cinnamic acid prevailed in the leaves of R. acetosella and A. ursinum (up to 4.81%. [Projekat Ministarstva nauke Republike Srbije, br. 173018

  5. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    Science.gov (United States)

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria.

  6. The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses

    Directory of Open Access Journals (Sweden)

    Lindinger Michael I

    2007-12-01

    Full Text Available Abstract Aim Sodium acetate (NaAcetate has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial; or 2 a hay/grain meal alone (Control trial. Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse.

  7. Safety and determination benzoic acid and sodium benzoate%苯甲酸和苯甲酸钠安全性与检测方法研究进展

    Institute of Scientific and Technical Information of China (English)

    李菊; 刘淑君; 黄雪琳

    2012-01-01

      As one of the acidic preservative,the abuse of benzoic acid and sodium benzoate is very dangerous. Because the residue of benzoic acid and sodium benzoate would do great harm to the human health even cause cancer after they were taken through the food and medicament. The researchers have dedicated many efforts to research for residue determination of benzoic acid and Sodium Benzoate. The security and methods for benzoic acid and sodium benzoate detection were summarized. this study was useful for the detecting technology of benzoic acid and sodium benzoate residues.%  苯甲酸和苯甲酸钠是一种酸性防腐剂,过量滥用很危险;因苯甲酸和苯甲酸钠被人体过量摄入后,会对人体健康造成极大危害,甚至致癌。该文对苯甲酸和苯甲酸钠残留安全性及检测方法进行综述,以期为苯甲酸和苯甲酸钠残留检测方法研究提供参考。

  8. 4-[(E-(5-tert-Butyl-2-hydroxyphenyldiazenyl]benzoic acid benzene hemisolvate

    Directory of Open Access Journals (Sweden)

    Edward R. T. Tiekink

    2010-03-01

    Full Text Available The title benzene hemisolvate, C17H18N2O3·0.5C6H6, features an essentially planar (the r.m.s. deviation of the non-H atoms, excluding methyl-C, is 0.071 Å diazo molecule with an E conformation about the N=N bond, and a half-molecule of benzene disposed about a centre of inversion. The dihedral angle formed between the benzene rings of the diazo molecule is 7.69 (12°. In the crystal, centrosymmetrically related dimers associate via the eight-membered carboxylic acid dimer synthon, {...HOC(=O}2, and these are connected into a supramolecular chain along the b axis via C—H...O contacts.

  9. Overexpression of acetyl-CoA synthetase in Saccharomyces cerevisiae increases acetic acid tolerance.

    Science.gov (United States)

    Ding, Jun; Holzwarth, Garrett; Penner, Michael H; Patton-Vogt, Jana; Bakalinsky, Alan T

    2015-01-01

    Acetic acid-mediated inhibition of the fermentation of lignocellulose-derived sugars impedes development of plant biomass as a source of renewable ethanol. In order to overcome this inhibition, the capacity of Saccharomyces cerevisiae to synthesize acetyl-CoA from acetic acid was increased by overexpressing ACS2 encoding acetyl-coenzyme A synthetase. Overexpression of ACS2 resulted in higher resistance to acetic acid as measured by an increased growth rate and shorter lag phase relative to a wild-type control strain, suggesting that Acs2-mediated consumption of acetic acid during fermentation contributes to acetic acid detoxification.

  10. Acetic Acid Causes Endoplasmic Reticulum Stress and Induces the Unfolded Protein Response in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Nozomi Kawazoe

    2017-06-01

    Full Text Available Since acetic acid inhibits the growth and fermentation ability of Saccharomyces cerevisiae, it is one of the practical hindrances to the efficient production of bioethanol from a lignocellulosic biomass. Although extensive information is available on yeast response to acetic acid stress, the involvement of endoplasmic reticulum (ER and unfolded protein response (UPR has not been addressed. We herein demonstrated that acetic acid causes ER stress and induces the UPR. The accumulation of misfolded proteins in the ER and activation of Ire1p and Hac1p, an ER-stress sensor and ER stress-responsive transcription factor, respectively, were induced by a treatment with acetic acid stress (>0.2% v/v. Other monocarboxylic acids such as propionic acid and sorbic acid, but not lactic acid, also induced the UPR. Additionally, ire1Δ and hac1Δ cells were more sensitive to acetic acid than wild-type cells, indicating that activation of the Ire1p-Hac1p pathway is required for maximum tolerance to acetic acid. Furthermore, the combination of mild acetic acid stress (0.1% acetic acid and mild ethanol stress (5% ethanol induced the UPR, whereas neither mild ethanol stress nor mild acetic acid stress individually activated Ire1p, suggesting that ER stress is easily induced in yeast cells during the fermentation process of lignocellulosic hydrolysates. It was possible to avoid the induction of ER stress caused by acetic acid and the combined stress by adjusting extracellular pH.

  11. Acetic Acid Causes Endoplasmic Reticulum Stress and Induces the Unfolded Protein Response in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kawazoe, Nozomi; Kimata, Yukio; Izawa, Shingo

    2017-01-01

    Since acetic acid inhibits the growth and fermentation ability of Saccharomyces cerevisiae, it is one of the practical hindrances to the efficient production of bioethanol from a lignocellulosic biomass. Although extensive information is available on yeast response to acetic acid stress, the involvement of endoplasmic reticulum (ER) and unfolded protein response (UPR) has not been addressed. We herein demonstrated that acetic acid causes ER stress and induces the UPR. The accumulation of misfolded proteins in the ER and activation of Ire1p and Hac1p, an ER-stress sensor and ER stress-responsive transcription factor, respectively, were induced by a treatment with acetic acid stress (>0.2% v/v). Other monocarboxylic acids such as propionic acid and sorbic acid, but not lactic acid, also induced the UPR. Additionally, ire1Δ and hac1Δ cells were more sensitive to acetic acid than wild-type cells, indicating that activation of the Ire1p-Hac1p pathway is required for maximum tolerance to acetic acid. Furthermore, the combination of mild acetic acid stress (0.1% acetic acid) and mild ethanol stress (5% ethanol) induced the UPR, whereas neither mild ethanol stress nor mild acetic acid stress individually activated Ire1p, suggesting that ER stress is easily induced in yeast cells during the fermentation process of lignocellulosic hydrolysates. It was possible to avoid the induction of ER stress caused by acetic acid and the combined stress by adjusting extracellular pH.

  12. KINETIC STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A NOVEL COPOLYMER- BOUND CIS- DICARBONYLRHODIUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuying; YUAN Guoqing; CHEN Rongyao

    1989-01-01

    The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh)coordinated with the ethylene diacrylate (M')crosslinked copolymer of methyl acrylate (M) and 2 - vinylpyridine (V) shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex . Polar solvents can accelerate the reaction .Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system . A mechanism similar to that of soluble rhodium catalyst was proposed .

  13. HPLC法测定酸奶中苯甲酸和山梨酸%The Determination of Benzoic Acid and Sorbic Acid in Yogurt by High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    冯金荣; 彭剑峰; 刘芳

    2012-01-01

    High performance liquid chromatography is established to determine benzoic acid and sorbic acid in yogurt. The lead acetate, potassium oxalate monohydrate and potassium phosphate dibasic solutions are used as deposit. The separation of two compounds is based on C18 column (150mm X 2.1ram i. d 5gin)and 10 % acetonitrile and 90% phosphoricacid salt buffer solution(pH 6. 7)as the mobile phase. The reaction is recorded by utraviolet detector. The ration of precision is 1. 69%and 2.2%, the average ration of recovery is 95.8% and 99.6%. The results are satisfactory.%用HPLC法对酸奶中的苯甲酸和山梨酸进行测定;醋酸铅、草酸钾-磷酸氢二钾溶液处理样品,C18柱(150mm×2.1mm i.d5pm)分离,流动相:乙腈:磷酸盐缓冲液(pH6.7)= 1:9,紫外检测器于227nm检测。该方法能对酸奶中苯甲酸和山梨酸很好分离,RSD分别为1.69%和2.2%,平均回收率分别是95.8%和99.6%,结果满意。

  14. Acetic acid bacteria spoilage of bottled red wine -- a review.

    Science.gov (United States)

    Bartowsky, Eveline J; Henschke, Paul A

    2008-06-30

    Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine.

  15. Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid

    Science.gov (United States)

    Negron-Mendoza, A.; Ponnamperuma, C.

    1976-01-01

    Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

  16. Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid

    Science.gov (United States)

    Negron-Mendoza, A.; Ponnamperuma, C.

    1976-01-01

    Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

  17. Adsorption Behaviour of Benzoic Acid in Water on Modified Bentonite%改性膨润土对水中苯甲酸的吸附

    Institute of Scientific and Technical Information of China (English)

    杨健; 辛晓东; 魏琴; 杜斌

    2012-01-01

    采用氯化钠对膨润土进行钠化,与聚二甲基二烯丙基氯化铵(PDMDAAC)作用制得PDMDAAC-膨润土.经FTIR 分析,研究PDMDAAC-膨润土对水中苯甲酸的最佳吸附条件、吸附动力学及等温线拟合.结果表明:当选取吸附剂用量为0.5g,吸附时间为1h,吸附酸度为pH =4时,PDMDAAC-膨润土可吸附0.5 mmol/L的苯甲酸,其最大吸附效率可达86.57%.PDMDAAC -膨润土对苯甲酸的吸附符合拟二级动力学方程及Langmuir型等温曲线.%Using sodium modified bentonite and polydimethydiallylammonium chloride, we prepared polydimethydiallylammonium chloride-bentonite ( PDMDAAC-bentonite) via exchange reaction and analyzed it by FTTR. The adsorption behavior of benzoic acid by PDMDAAC-bentonite was studied,and the best experimental conditions were investigated. Experimental results show that PDMDAAC-bentonite can adsorb 0.5 mmol/L benzoic acid with the maximal removal efficiency of 86. 57% under the optimial conditons of 0. 5 g sorbent,1 h adsorption time and pH =4. The adsorption kinetic data of benzoic acid by PDMDAAC-bentonite fitts the pseudo-second-order model well, and its adsorption isotherm meets with Langmuir adsorption model.

  18. Nano-composite polymer gel electrolytes containing ortho-nitro benzoic acid: role of dielectric constant of solvent and fumed silica

    Science.gov (United States)

    Kumar, R.

    2015-03-01

    In this paper, nano-composite polymer gel electrolytes containing polymethylmethacrylate, dimethylacetamide, diethyl carbonate, fumed silica and ortho-nitro benzoic acid have been synthesized. Electrical conductivity, viscosity, pH and thermal behavior of these electrolytes have been studied. The effect of acid, polymer, fumed silica concentration on conductivity, pH and viscosity has been discussed. The effect of dielectric constant of solvent on conductivity behavior of composite polymer gel electrolytes has also been studied. Two maxima in conductivity behavior have been observed with fumed silica concentration for composite polymer gel electrolytes, which have been explained on the basis of double percolation threshold model. Maximum conductivity of 3.20 × 10-4 and 2.46 × 10-6 S/cm at room temperature has been observed for nano-composite polymer gel electrolytes containing 10 wt% polymethylmethacrylate in 1 M solution of o-nitro benzoic acid in dimethylacetamide and diethyl carbonate respectively. The intensity of first maximum observed in conductivity at low concentration of fumed silica has been found to decrease with the decrease in acid concentration for composite polymer gel electrolytes, while the intensity of second maximum at higher fumed silica concentration remains unaffected. The conductivity of composite gels does not show much change in the temperature range of 20-100 °C and also remains constant with time, making them suitable for use as electrolytes in various devices like fuel cells, proton batteries, electrochromic window applications etc.

  19. Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2014-09-01

    An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

  20. Kinetics of esterification of methanol and acetic acid with mineral homogeneous acid catalyst

    Institute of Scientific and Technical Information of China (English)

    Mallaiah Mekala; Venkat Reddy Goli

    2015-01-01

    In this work, esterification of acetic acid and methanol to synthesize methyl acetate in a batch stirred reactor is studied in the temperature range of 305.15–333.15 K. Sulfuric acid is used as the homogeneous catalyst with concentrations ranging from 0.0633 mol·L−1 to 0.3268 mol·L−1. The feed molar ratio of acetic acid to methanol is varied from 1:1 to 1:4. The influences of temperature, catalyst concentration and reactant concentration on the reaction rate are investigated. A second order kinetic rate equation is used to correlate the experimental data. The forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot. The developed kinetic model is compared with the models in literature. The developed kinetic equation is useful for the simulation of reactive distillation column for the synthesis of methyl acetate.

  1. Synthesis of Isocoumarins from Cyclic 2-Diazo-1,3-diketones and Benzoic Acids via Rh(III)-Catalyzed C-H Activation and Esterification.

    Science.gov (United States)

    Yang, Cheng; He, Xinwei; Zhang, Lanlan; Han, Guang; Zuo, Youpeng; Shang, Yongjia

    2017-02-17

    A mild and efficient Rh(III)-catalyzed C-H activation/esterification reaction for the synthesis of isocoumarins has been developed. This procedure uses readily available benzoic acids and cyclic diazo-1,3-diketones as starting materials and involves domino intermolecular C-H activation in combination with intramolecular esterification to give the corresponding isocoumarins in moderate to excellent yields. This process provides a facile approach for the construction of isocoumarins containing various functional groups that does not require any additives.

  2. Synthesis and Protective Effect of New Ligustrazine-Benzoic Acid Derivatives against CoCl2-Induced Neurotoxicity in Differentiated PC12 Cells

    Directory of Open Access Journals (Sweden)

    Haimin Lei

    2013-10-01

    Full Text Available A series of novel ligustrazine-benzoic acid derivatives were synthesized and evaluated for their protective effect against cobalt chloride-induced neurotoxicity in differentiated PC12 cells. Combining hematoxylin and eosin staining, we found compound that (3,5,6-trimethylpyrazin-2-ylmethyl 3-methoxy-4-[(3,5,6-trimethylpyrazin-2-ylmethoxy]benzoate (4a displayed promising protective effect on the proliferation of the injured PC12 cells (EC50 = 4.249 µM. Structure-activity relationships are briefly discussed.

  3. EFFECT OF GOSSYPOL ACETIC ACID ON CHROMOSOME ABERRATIONS AND ANEUPLOIDIES IN OOCYTES AND ZYGOTES OF MICE

    Institute of Scientific and Technical Information of China (English)

    WANGRen-Li; ZHANGZhong-Shu

    1989-01-01

    It was reported that gossypol acetic acid could effectively inhibit th~ implantation in ratA. This finding indicated that gossypol acet/c acid might also be used as a female contraceptive. The Present study further investigated the genetic effect of gossypol acetic

  4. Conversion regular patterns of acetic acid,propionic acid and butyric acid in UASB reactor

    Institute of Scientific and Technical Information of China (English)

    LIU Min; REN Nan-qi; CHEN Ying; ZHU Wen-fang; DING Jie

    2004-01-01

    On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbial is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used,the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol-type fermentation of the acidogenic-phase is the optimal acid-type fermentation for the two-phase anaerobic process.

  5. Liquid phase ozonation of cyclohexanol using acetic acid as solvent

    Energy Technology Data Exchange (ETDEWEB)

    Encinar, J.M.; Beltran, F.J. (Departamento de Ingeneria Quimica y Energetica. Facultad de Ciencias. Badajoz (Spain)); Frades, J.M. (Departamento de Ingenieria Quimica. E.U.P. Almaden (Spain))

    1994-01-01

    The liquid phase oxidation of cyclohexanol in an acetic acid medium using a mixture of oxygen and ozone has been studied in a laboratory semi batch reactor. The influence of temperature, ozone partial pressure, initial concentration of cyclohexanol on its conversion and yield and distribution of products has been observed. Under the experimental conditions investigated formation of peroxydic compounds and mono basic acids was not relevant; the major products obtained were cyclohexanone and adipic and glutaric acids although analytical chromatograms revealed the presence of other products unidentified. Formation of these products is qualitatively explained by means of a chain-radical mechanism. Finally, it is proposed an empirical kinetic equation which relates the variables mentioned above with the reaction rates. This equation reproduces the experimental results with deviations less than 10%. (Author) 21 refs.

  6. Probiotic and Acetic Acid Effect on Broiler Chickens Performance

    Directory of Open Access Journals (Sweden)

    Martin Král

    2011-05-01

    Full Text Available Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drinking water and probiotics mixed with feed mixture. Body weight, FCR and GIT pH were recorded. The performance showed no statistically significant increase in body weight (P>0.05 in the weeks 1, 2, 3 and 4 of age. The body weight of broiler chickens was significant increase (P0.05 in weeks 5, and 6 of age. In different segments of the GIT was not statistically significant (P>0.05 difference of pH between the control and experimental groups.

  7. Olfactory attraction of Drosophila suzukii by symbiotic acetic acid bacteria

    KAUST Repository

    Mazzetto, Fabio

    2016-03-24

    Some species of acetic acid bacteria (AAB) play relevant roles in the metabolism and physiology of Drosophila spp. and in some cases convey benefits to their hosts. The pest Drosophila suzukii harbors a set of AAB similar to those of other Drosophila species. Here, we investigate the potential to exploit the ability of AAB to produce volatile substances that attract female D. suzukii. Using a two-way olfactometer bioassay, we investigate the preference of D. suzukii for strains of AAB, and using solid-phase microextraction gas chromatography–mass spectrometry we specifically characterize their volatile profiles to identify attractive and non-attractive components produced by strains from the genera Acetobacter, Gluconobacter, and Komagataeibacter. Flies had a preference for one strain of Komagataeibacter and two strains of Gluconobacter. Analyses of the volatile profiles from the preferred Gluconobacter isolates found that acetic acid is distinctively emitted even after 2 days of bacterial growth, confirming the relevance of this volatile in the profile of this isolate for attracting flies. Analyses of the volatile profile from the preferred Komagataeibacter isolate showed that a different volatile in its profile could be responsible for attracting D. suzukii. Moreover, variation in the concentration of butyric acid derivatives found in some strains may influence the preference of D. suzukii. Our results indicate that Gluconobacter and Komagataeibacter strains isolated from D. suzukii have the potential to provide substances that could be exploited to develop sustainable mass-trapping-based control approaches. © 2016 Springer-Verlag Berlin Heidelberg

  8. Free acetate production by rat hepatocytes during peroxisomal fatty acid and dicarboxylic acid oxidation.

    Science.gov (United States)

    Leighton, F; Bergseth, S; Rørtveit, T; Christiansen, E N; Bremer, J

    1989-06-25

    The fate of the acetyl-CoA units released during peroxisomal fatty acid oxidation was studied in isolated hepatocytes from normal and peroxisome-proliferated rats. Ketogenesis and hydrogen peroxide generation were employed as indicators of mitochondrial and peroxisomal fatty acid oxidation, respectively. Butyric and hexanoic acids were employed as mitochondrial substrates, 1, omega-dicarboxylic acids as predominantly peroxisomal substrates, and lauric acid as a substrate for both mitochondria and peroxisomes. Ketogenesis from dicarboxylic acids was either absent or very low in normal and peroxisome-proliferated hepatocytes, but free acetate release was detected at rates that could account for all the acetyl-CoA produced in peroxisomes by dicarboxylic and also by monocarboxylic acids. Mitochondrial fatty acid oxidation also led to free acetate generation but at low rates relative to ketogenesis. The origin of the acetate released was confirmed employing [1-14C]dodecanedioic acid. Thus, the activity of peroxisomes might contribute significantly to the free acetate generation known to occur during fatty acid oxidation in rats and possibly also in humans.

  9. Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2–Acetic Acid Interface

    Science.gov (United States)

    2016-01-01

    The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC. PMID:27110318

  10. Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2-Acetic Acid Interface.

    Science.gov (United States)

    Hussain, Hadeel; Torrelles, Xavier; Cabailh, Gregory; Rajput, Parasmani; Lindsay, Robert; Bikondoa, Oier; Tillotson, Marcus; Grau-Crespo, Ricardo; Zegenhagen, Jörg; Thornton, Geoff

    2016-04-14

    The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC.

  11. Induced Smectic X Phase Through Intermolecular Hydrogen-Bonded Liquid Crystals Formed Between Citric Acid and p- n-(Octyloxy)Benzoic Acid

    Science.gov (United States)

    Sundaram, S.; Subhasri, P.; Rajasekaran, T. R.; Jayaprakasam, R.; Senthil, T. S.; Vijayakumar, V. N.

    2017-08-01

    Hydrogen-bonded liquid crystal (HBLC) is synthesized from citric acid (CA) and 4-(octyloxy)benzoic acid (8OBA) with different mole ratios. Fourier transform infrared spectroscopy (FT-IR) confirms the presence of hydrogen bond between CA and 8OBA. Nuclear magnetic resonance (NMR) spectroscopic studies validate the intermolecular complementary, cyclic type of hydrogen bond, and molecular environment in the designed HBLC complex. Powder X-ray diffraction analysis reveals the monoclinic nature of liquid crystal complex in solid phase. Liquid crystal parameters such as phase transition temperature and enthalpy values for the corresponding mesogenic phases are investigated using a polarizing optical microscope (POM) and differential scanning calorimetry (DSC). It is observed that the change in chain length and steric hindrance while increasing the mole ratio in HBLC complex induces a new smectic X (Sm X) along with higher-order smectic G (Sm G) phases by quenching of smectic C (Sm C). From the experimental observations, induced Sm X phase has been identified as a finger print texture. Also, Sm G is a multi-colored mosaic texture in 1:1, 1:2, and 1:3 mol ratios. The optical tilt angle, thermal stability factor, and enhanced thermal span width of CA + 8OBA complex are discussed.

  12. Characterization of inhibitory effects of the potential therapeutic inhibitors, benzoic acid and pyridine derivatives, on the monophenolase and diphenolase activities of tyrosinase

    Directory of Open Access Journals (Sweden)

    Nematollah Gheibi

    2015-02-01

    Full Text Available Objective(s:Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. Materials and Methods: In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-amino benzoic acid, 4-amino benzoic acid, nicotinic acid, and picolinic acid on the monophenolase and diphenolase activities of the mushroom tyrosinase, and then MTT assay was exploited to evaluate their toxicity on the melanoma cells. Results: Kinetic analysis revealed that nicotinic acid and picolinic acid competitively restricted the monophenolase activity with inhibition constants (Ki of 1.21 mM and 1.97 mM and the diphenolase activity with Kis of 2.4 mM and 2.93 mM, respectively. 2-aminobenzoic acid and 4-aminobenzoic acid inhibited the monophenolase activity in a non-competitive fashion with Kis of 5.15 µM and 3.8 µM and the diphenolase activity with Kis of 4.72 µM and 20 µM, respectively. Conclusion: Our cell-based data revealed that only the pyridine derivatives imposed cytotoxicity in melanoma cells. Importantly, the concentrations of the inhibitors leading to 50% decrease in the cell density (IC50 werecomparable to those causing 50% drop in the enzyme activity, implying that the observed cytotoxicity is highly likely due to the tyrosinase inhibition. Moreover, our cell-based data exhibited that the pyridine derivatives acted as anti-proliferative agents, perhaps inducing cytotoxicity in the melanoma cells through inhibition of the tyrosinase activities.

  13. Simultaneous determination of salicylic, 3-methyl salicylic, 4-methyl salicylic, acetylsalicylic and benzoic acids in fruit, vegetables and derived beverages by SPME-LC-UV/DAD.

    Science.gov (United States)

    Aresta, Antonella; Zambonin, Carlo

    2016-03-20

    Salicylic and benzoic acid are phenolic acids occurring in plant cells, thus they can be present in fruit and vegetables at various levels. They possess anti-inflammatory and antimicrobial properties, however they may induce symptoms and health problems in a small percentage of the population. Therefore, a low phenolic acid diet may be of clinical benefit to such individuals. In order to achieve this goal, the concentration of these substances in different food and beverages should be assessed. The present work describes for the first time a new method, based on solid phase microextraction (polydimethylsiloxane-divinylbenzene fiber) coupled to liquid chromatography with UV diode array detection, for the simultaneous determination of salicylic acid, 3-methyl salicylic acid, 4-methyl salicylic acid, acetylsalicylic acid and benzoic acid in selected fruit, vegetables and beverages. All the aspects influencing fiber adsorption (time, temperature, pH, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition) of the analytes have been investigated. An isocratic separation was performed using an acetonitrile-phosphate buffer (pH 2.8; 2 mM) mixture (70:30, v/v) as the mobile phase. The estimated LOD and LOQ values (μg/mL) were in the range 0.002-0.028 and 0.007-0.095. The within-day and day-to-day precision values (RSD%) were between 4.7-6.1 and 6.6-9.4, respectively. The method has been successfully applied to the analysis of fava beans, blueberries, kiwi, tangerines, lemons, oranges and fruit juice (lemon and blueberry) samples. The major advantage of the method is that it only requires simple homogenization and/or centrifugation and dilution steps prior to SPME and injection in the LC system.

  14. Improvement of acetic acid tolerance of Saccharomyces cerevisiae using a zinc-finger-based artificial transcription factor and identification of novel genes involved in acetic acid tolerance.

    Science.gov (United States)

    Ma, Cui; Wei, Xiaowen; Sun, Cuihuan; Zhang, Fei; Xu, Jianren; Zhao, Xinqing; Bai, Fengwu

    2015-03-01

    Acetic acid is present in cellulosic hydrolysate as a potent inhibitor, and the superior acetic acid tolerance of Saccharomyces cerevisiae ensures good cell viability and efficient ethanol production when cellulosic raw materials are used as substrates. In this study, a mutant strain of S. cerevisiae ATCC4126 (Sc4126-M01) with improved acetic acid tolerance was obtained through screening strains transformed with an artificial zinc finger protein transcription factor (ZFP-TF) library. Further analysis indicated that improved acetic acid tolerance was associated with improved catalase (CAT) activity. The ZFP coding sequence associated with the improved phenotype was identified, and real-time RT-PCR analysis revealed that three of the possible genes involved in the enhanced acetic acid tolerance regulated by this ZFP-TF, namely YFL040W, QDR3, and IKS1, showed decreased transcription levels in Sc4126-M01 in the presence of acetic acid, compared to those in the control strain. Sc4126-M01 mutants having QDR3 and IKS1 deletion (ΔQDR3 and ΔIKS1) exhibited higher acetic acid tolerance than the wild-type strain under acetic acid treatment. Glucose consumption rate and ethanol productivity in the presence of 5 g/L acetic acid were improved in the ΔQDR3 mutant compared to the wild-type strain. Our studies demonstrated that the synthetic ZFP-TF library can be used to improve acetic acid tolerance of S. cerevisiae and that the employment of an artificial transcription factor can facilitate the exploration of novel functional genes involved in stress tolerance of S. cerevisiae.

  15. APMP.QM-S8: determination of mass fraction of benzoic acid, methyl paraben and n-butyl paraben in soy sauce

    Science.gov (United States)

    Teo, Tang Lin; Gui, Ee Mei; Lu, Ting; Sze Cheow, Pui; Giannikopoulou, Panagiota; Kakoulides, Elias; Lampi, Evgenia; Choi, Sik-man; Yip, Yiu-chung; Chan, Pui-kwan; Hui, Sin-kam; Wollinger, Wagner; Carvalho, Lucas J.; Garrido, Bruno C.; Rego, Eliane C. P.; Ahn, Seonghee; Kim, Byungjoo; Li, Xiuqin; Guo, Zhen; Styarini, Dyah; Aristiawan, Yosi; Putri Ramadhaningtyas, Dillani; Aryana, Nurhani; Ebarvia, Benilda S.; Dacuaya, Aaron; Tongson, Alleni; Aganda, Kim Christopher; Junvee Fortune, Thippaya; Tangtrirat, Pradthana; Mungmeechai, Thanarak; Ceyhan Gören, Ahmet; Gündüz, Simay; Yilmaz, Hasibe

    2017-01-01

    The supplementary comparison APMP.QM-S8: determination of mass fraction of benzoic acid, methyl paraben and n-butyl paraben in soy sauce was coordinated by the Health Sciences Authority, Singapore under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Ten national metrology institutes (NMIs) or designated institutes (DIs) participated in the comparison. All the institutes participated in the comparison for benzoic acid, while six NMIs/DIs participated in the comparison for methyl paraben and n-butyl paraben. The comparison was designed to enable participating institutes to demonstrate their measurement capabilities in the determination of common preservatives in soy sauce, using procedure(s) that required simple sample preparation and selective detection in the mass fraction range of 50 to 1000 mg/kg. The demonstrated capabilities can be extended to include other polar food preservatives (e.g. sorbic acid, propionic acid and other alkyl benzoates) in water, aqueous-based beverages (e.g. fruit juices, tea extracts, sodas, sports drinks, etc) and aqueous-based condiments (e.g. vinegar, fish sauce, etc). Liquid--liquid extraction and/or dilution were applied, followed by instrumental analyses using LC-MS/MS, LC-MS, GC-MS (with or without derivatisation) or HPLC-DAD. Isotope dilution mass spectrometry was used for quantification, except in the case of a participating institute, where external calibration method was used for quantification of all three measurands. The assigned Supplementary Comparison Reference Values (SCRVs) were the medians of ten results for benzoic acid, six results for methyl paraben and six results for n-butyl paraben. Benzoic acid was assigned a SCRV of 154.55 mg/kg with a combined standard uncertainty of 0.94 mg/kg, methyl paraben was assigned a SCRV of 100.95 mg/kg with a combined standard uncertainty of 0.40 mg/kg, and n-butyl paraben was assigned a SCRV of 99.05 mg

  16. 75 FR 40736 - Acetic Acid; Exemption from the Requirement of a Tolerance

    Science.gov (United States)

    2010-07-14

    ..., particularly in the tricarboxylic acid cycle, also known as the citric acid (Ref. 1.) or krebs cycle (Ref. 2... AGENCY 40 CFR Part 180 Acetic Acid; Exemption from the Requirement of a Tolerance AGENCY: Environmental... for acetic acid by establishing an exemption from the requirement of a tolerance for residues of...

  17. Crystal structures of hydrogen-bonded co-crystals as liquid crystal precursors: 4-(n-pent-yloxy)benzoic acid-(E)-1,2-bis-(pyridin-4-yl)ethene (2/1) and 4-(n-hex-yloxy)benzoic acid-(E)-1,2-bis-(pyridin-4-yl)ethene (2/1).

    Science.gov (United States)

    Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

    2016-12-01

    The crystal structures of title hydrogen-bonded co-crystals, 2C12H16O3·C12H10N2, (I), and 2C13H18O3·C12H10N2, (II), have been determined at 93 K. In (I), the asymmetric unit consists of one 4-(n-pent-yloxy)benzoic acid mol-ecule and one half-mol-ecule of (E)-1,2-bis-(pyridin-4-yl)ethene, which lies about an inversion centre. The asymmetric unit of (II) comprises two crystallographically independent 4-(n-hex-yloxy)benzoic acid mol-ecules and one 1,2-bis-(pyridin-4-yl)ethene mol-ecule. In each crystal, the acid and base components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1 unit of the acid and the base. The 2:1 units are linked via C-H⋯π and π-π inter-actions [centroid-centroid distances of 3.661 (2) and 3.909 (2) Å for (I), and 3.546 (2)-3.725 (4) Å for (II)], forming column structures. In (II), the base mol-ecule is orientationally disordered over two sets of sites approximately around the N⋯N mol-ecular axis, with an occupancy ratio of 0.647 (4):0.353 (4), and the average structure of the 2:1 unit adopts nearly pseudo-C2 symmetry. Both compounds show liquid-crystal behaviour.

  18. Unusal pattern of product inhibition: batch acetic acid fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Bar, R.; Gainer, J.L.; Kirwan, D.J.

    1987-04-20

    The limited tolerance of microorganisms to their metabolic products results in inhibited growth and product formation. The relationship between the specific growth rate, micro, and the concentration of an inhibitory product has been described by a number of mathematical models. In most cases, micro was found to be inversely proportional to the product concentration and invariably the rate of substrate utilization followed the same pattern. In this communication, the authors report a rather unusual case in which the formation rate of a product, acetic acid, increased with a decreasing growth rate of the microorganism, Acetobacter aceti. Apparently, a similar behavior was mentioned in a review report with respect to Clostridium thermocellum in a batch culture but was not published in the freely circulating literature. The fermentation of ethanol to acetic acid, C/sub 2/H/sub 5/OH + O/sub 2/ = CH/sub 3/COOH + H/sub 2/O is clearly one of the oldest known fermentations. Because of its association with the commercial production of vinegar it has been a subject of extensive but rather technically oriented studies. Suprisingly, the uncommon uncoupling between the inhibited microbial growth and the product formation appears to have been unnoticed. 13 references.

  19. Required catalytic properties for alkane production from carboxylic acids: Hydrodeoxygenation of acetic acid

    Institute of Scientific and Technical Information of China (English)

    Zhong; He; Xianqin; Wang

    2013-01-01

    The supported Pt catalysts(1 wt%)were prepared by the incipient impregnation method and analyzed using synchrotron-based X-ray diffraction,BET surface area,oxygen adsorption,CO pulse chemisorption,temperature-programmed desorption(TPD)of acetic acid,H2-TPD,NH3-TPD,O2-TPD,and H2-TPR.The reactivity of Pt-based catalysts was studied using a fixed bed reactor at 300 C and 4 MPa for hydrodeoxygenation of acetic acid,where Pt/TiO2 was very selective for ethane production.TPD experiments revealed that several conditions must be satisfied to achieve this high selectivity to ethane from acetic acid,such as Pt sites,moderate acidity,and medium metal-oxygen bond strength in the oxide support.This work provides insights in developing novel catalytic materials for hydrocarbon productions from various organics including bio-fuels.

  20. Selenium dioxide catalysed oxidation of acetic acid hydrazide by bromate in aqueous hydrochloric acid medium

    Indian Academy of Sciences (India)

    R S Yalgudre; G S Gokavi

    2012-07-01

    Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The order in oxidant concentration, substrate and catalyst were found to be unity. Increasing hydrogen ion concentration increases the rate of the reaction due to protonation equilibria of the oxidant. The mechanism of the reaction involves prior complex formation between the catalyst and substrate, hydrazide, followed by its oxidation by diprotonated bromate in a slow step. Acetic acid was found to be the oxidation product. Other kinetic data like effect of solvent polarity and ionic strength on the reaction support the proposed mechanism.

  1. Ionic liquid mediated esterification of alcohol with acetic acid

    Institute of Scientific and Technical Information of China (English)

    Beilei ZHOU; Yanxiong FANG; Hao GU; Saidan ZHANG; Baohua HUANG; Kun ZHANG

    2009-01-01

    Highly efficient esterification of alcohols with acetic acid by using a Bransted acidic ionic liquid, i.e., 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSo4), as catalyst has been realized. The turnover numbers (TON) were able to reach up to 11000 and turnover frequency (TOF) was 846. The catalytic system is suitable for the esterification of long chain aliphatic alcohols, benzyl alcohol and cyclohexanol with good yields of esters. The procedure of separating the product and catalyst is simple, and the catalyst could be reused. [Hnmp]HSO4 had much weaker corrosiveness than H2SO4. The corrosive rate of H2SO4 was 400 times more than that of [Hnmp]HSO4 to stainless steel.

  2. 苯甲酸溶解度的测定及关联%Measurement and Correlation of Solubilities of Benzoic Acid in Different Solvents

    Institute of Scientific and Technical Information of China (English)

    刘江刍鸟; 李殿卿; 刘大壮; 陈忠民; 田洪河

    2001-01-01

    Using a laser monitoring observation technique,the solubilities of benzoic acid in trichloromethane,N,N-dimethylformamide,N,N-dimethylacetamide and N-Methyl-2-pyrrolidonewere,which has never been seen in literatures before,are determined by the synthetic method.To verify the reliability of the experimental method,the solubility of benzoic acid in water was measured before the experiments,which shows excellent consistency with the literature data.By means of Apelblat's solubility model to correlate the experimental results,the calculated solubilities show good agreement with the experimental values.%为了回收、提纯PTA氧化残渣中的苯甲酸,采用激光监视技术由合成法测定了鲜见文献报道的苯甲酸在氯仿、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺、N-甲基吡咯烷酮中的溶解度.为了验证测定方法的可靠性,事先测定了苯甲酸在水、醋酸中的溶解度,与已有文献数据相比,一致性较好.用Apelblat等人提出的溶解度模型对实验数据进行关联,计算的溶解度与实验值符合良好.

  3. Effect of manganese and potassium addition on CeO2-Al2O3 catalyst for hydrogenation of benzoic acid to benzaldehyde

    Institute of Scientific and Technical Information of China (English)

    CHENG; Dangguo; HOU; Chunyang; CHEN; Fengqiu; ZHAN; Xiaol

    2009-01-01

    A series of Mn/CeO2-Al2O3 and K/CeO2-Al2O3 catalysts for hydrogenation of benzoic acid to benzaldehyde were prepared to in-vestigate the effect of Mn, K addition on CeO2-Al2O3 catalyst. X-ray diffraction (XRD) and H2-temperature-programmed reduction (H2-TPR) results suggested that the interaction between CeO2 and MnOx enhanced the reducibility of catalysts and therefore benzoic acid conversion.The addition of K increased the number of basic number on the catalyst which leads to a high selectivity to benzaldehyde, but excessive addition imposed negative effects on the catalyst performance. A Mn-K/CeO2Al2O3 catalyst was developed and investigated in the reaction. The simul-taneous addition of Mn and K enhanced not only the catalytic activity but also the capacity to resist the coke formation over catalyst.

  4. Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-01-01

    Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 °C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic...

  5. Interaction effects of lactic acid and acetic acid at different temperatures on ethanol production by Saccharomyces cerevisiae in corn mash.

    Science.gov (United States)

    Graves, Tara; Narendranath, Neelakantam V; Dawson, Karl; Power, Ronan

    2007-01-01

    The combined effects of lactic acid and acetic acid on ethanol production by S. cerevisiae in corn mash, as influenced by temperature, were examined. Duplicate full factorial experiments (three lactic acid concentrations x three acetic acid concentrations) were performed to evaluate the interaction between lactic and acetic acids on the ethanol production of yeast at each of the three temperatures, 30, 34, and 37 degrees C. Corn mash at 30% dry solids adjusted to pH 4 after lactic and acetic acid addition was used as the substrate. Ethanol production rates and final ethanol concentrations decreased (Plactic and acetic acids in the corn mash increased and the temperature was raised from 30 to 37 degrees C. At 30 degrees C, essentially no ethanol was produced after 96 h when 0.5% w/v acetic acid was present in the mash (with 0.5, 2, and 4% w/v lactic acid). At 34 and 37 degrees C, the final concentrations of ethanol produced by the yeast were noticeably reduced by the presence of 0.3% w/v acetic acid and >or=2% w/v lactic acid. It can be concluded that, as in previous studies with defined media, lactic acid and acetic acid act synergistically to reduce ethanol production by yeast in corn mash. In addition, the inhibitory effects of combined lactic and acetic acid in corn mash were more apparent at elevated temperatures.

  6. Heterogeneous Reactions of Acetic Acid with Oxide Surfaces: Effects of Mineralogy and Relative Humidity.

    Science.gov (United States)

    Tang, Mingjin; Larish, Whitney A; Fang, Yuan; Gankanda, Aruni; Grassian, Vicki H

    2016-07-21

    We have investigated the heterogeneous uptake of gaseous acetic acid on different oxides including γ-Al2O3, SiO2, and CaO under a range of relative humidity conditions. Under dry conditions, the uptake of acetic acid leads to the formation of both acetate and molecularly adsorbed acetic acid on γ-Al2O3 and CaO and only molecularly adsorbed acetic acid on SiO2. More importantly, under the conditions of this study, dimers are the major form for molecularly adsorbed acetic acid on all three particle surfaces investigated, even at low acetic acid pressures under which monomers are the dominant species in the gas phase. We have also determined saturation surface coverages for acetic acid adsorption on these three oxides under dry conditions as well as Langmuir adsorption constants in some cases. Kinetic analysis shows that the reaction rate of acetic acid increases by a factor of 3-5 for γ-Al2O3 when relative humidity increases from 0% to 15%, whereas for SiO2 particles, acetic acid and water are found to compete for surface adsorption sites.

  7. Acetic acid induces pH-independent cellular energy depletion in Salmonella enterica.

    Science.gov (United States)

    Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A

    2015-03-01

    Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (pacid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56 ± 1.27; pacid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH.

  8. Benzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids.

    Science.gov (United States)

    Banerjee, Amit; Senthilkumar, Soundararasu; Baskaran, Sundarababu

    2016-01-18

    Direct oxidation of the 4,6-O-benzylidene acetal protecting group to C-6 carboxylic acid has been developed that provides an easy access to a wide range of biologically important and synthetically challenging uronic acid and sugar amino acid derivatives in good yields. The RuCl3 -NaIO4 -mediated oxidative cleavage method eliminates protection and deprotection steps and the reaction takes place under mild conditions. The dual role of the benzylidene acetal, as a protecting group and source of carboxylic acid, was exploited in the efficient synthesis of six-carbon sialic acid analogues and disaccharides bearing uronic acids, including glycosaminoglycan analogues.

  9. Performance of a growth-no growth model for Listeria monocytogenes developed for mayonnaise-based salads: influence of strain variability, food matrix, inoculation level, and presence of sorbic and benzoic acid.

    Science.gov (United States)

    Vermeulen, A; Smigic, N; Rajkovic, A; Gysemans, K; Bernaerts, K; Geeraerd, A; Van Impe, J; Debevere, J; Devlieghere, F

    2007-09-01

    A previously developed growth-no growth model for Listeria monocytogenes, based on nutrient broth data and describing the influence of water activity (a(w)), pH, and acetic acid concentrations, was validated (i) for a variety of L. monocytogenes strains and (ii) in a laboratory-made, mayonnaise-based surimi salad (as an example of a mayonnaise-based salad). In these challenge tests, the influence of the inoculation level was tested as well. Also, the influence of chemical preservatives on the growth probability of L. monocytogenes in mayonnaise-based salads was determined. To evaluate the growth-no growth model performance on the validation data, four quantitative criteria are determined: concordance index, % correct predictions, % fail-dangerous, and % fail-safe. First, the growth probability of 11 L. monocytogenes strains, not used for model development, was assessed in nutrient broth under conditions within the interpolation region. Experimental results were compared with model predictions. Second, the growth-no growth model was assessed in a laboratory-made, sterile, mayonnaise-based surimi salad to identify a possible model completeness error related to the food matrix, making use of the above-mentioned validation criteria. Finally, the effect on L. monocytogenes of common chemical preservatives (sorbic and benzoic acid) at different concentrations under conditions typical of mayonnaise-based salads was determined. The study showed that the growth-no growth zone was properly predicted and consistent for all L. monocytogenes strains. A larger prediction error was observed under conditions within the transition zone between growth-no growth. However, in all cases, the classification between no growth (P = 0) and any growth (P > 0) occurred properly, which is most important for the food industry, where outgrowth needs to be prevented in all instances. The results in the sterile mayonnaise-based salad showed again that the growth-no growth zone was well predicted

  10. Clostridium lentocellum SG6--a potential organism for fermentation of cellulose to acetic acid.

    Science.gov (United States)

    Ravinder, T; Swamy, M V; Seenayya, G; Reddy, G

    2001-12-01

    A cellulolytic, acetic acid producing anaerobic bacterial isolate, Gram negative, rod-shaped, motile, terminal oval shaped endospore forming bacterium identified as Clostridium lentocellum SG6 based on physiological and biochemical characteristics. It produced acetic acid as a major end product from cellulose fermentation at 37 degrees C and pH 7.2. Acetic acid production was 0.67 g/g cellulose substrate utilized in cellulose mineral salt (CMS) medium. Yeast extract (0.4%) was the best nitrogen source among the various nitrogenous nutrients tested in production medium containing 0.8% cellulose as substrate. No additional vitamins or trace elemental solution were required for acetic acid fermentation. This is the highest acetic acid fermentation yield in monoculture fermentation for direct conversion of cellulose to acetic acid.

  11. Study on fluorescence spectra of molecular association of acetic acid-water

    Institute of Scientific and Technical Information of China (English)

    Caiqin Han; Ying Liu; Yang Yang; Xiaowu Ni; Jian Lu; Xiaosen Luo

    2009-01-01

    Fluorescence spectra of acetic acid-water solution excited by ultraviolet (UV) light are studied, and the relationship between fluorescence spectra and molecular association of acetic acid is discussed. The results indicate that when the exciting light wavelength is longer than 246 nm, there are two fluorescence peaks located at 305 and 334 nm, respectively. By measuring the excitation spectra, the optimal wavelengths of the two fluorescence peaks are obtained, which are 258 and 284 nm, respectively. Fluorescence spectra of acetic acid-water solution change with concentrations, which is primarily attributed to changes of molecular association of acetic acid in aqueous solution. Through theoretical analysis, three variations of molecular association have been obtained in acetic acid-water solution, which are the hydrated monomers, the linear dimers, and the water separated dimers. This research can provide references to studies of molecular association of acetic acid-water, especially studies of hydrogen bonds.

  12. Recent advances in nitrogen-fixing acetic acid bacteria.

    Science.gov (United States)

    Pedraza, Raúl O

    2008-06-30

    Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects

  13. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    Energy Technology Data Exchange (ETDEWEB)

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  14. Improvement in HPLC separation of acetic acid and levulinic acid in the profiling of biomass hydrolysate.

    Science.gov (United States)

    Xie, Rui; Tu, Maobing; Wu, Yonnie; Adhikari, Sushil

    2011-04-01

    5-Hydroxymethylfurfural (HMF) and furfural could be separated by the Aminex HPX-87H column chromatography, however, the separation and quantification of acetic acid and levulinic acid in biomass hydrolysate have been difficult with this method. In present study, the HPLC separation of acetic acid and levulinic acid on Aminex HPX-87H column has been investigated by varying column temperature, flow rate, and sulfuric acid content in the mobile phase. The column temperature was found critical in resolving acetic acid and levulinic acid. The resolution for two acids increased dramatically from 0.42 to 1.86 when the column temperature was lowered from 60 to 30 °C. So did the capacity factors for levulinic acid that was increased from 1.20 to 1.44 as the column temperature dropped. The optimum column temperature for the separation was found at 45 °C. Variation in flow rate and sulfuric acid concentration improved not as much as the column temperature did.

  15. Dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid in PM2.5 aerosol collected during CAREBeijing-2007: an effect of traffic restriction on air quality

    Directory of Open Access Journals (Sweden)

    K. F. Ho

    2014-06-01

    Full Text Available Thirty water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids, and benzoic acid were determined as well as organic carbon (OC, elemental carbon (EC and water-soluble organic carbon (WSOC in PM2.5 samples collected during the Campaign of Air Quality Research in Beijing 2007 (CAREBeijing-2007 in the urban and suburban areas of Beijing. The objective of this study is to identify the influence of traffic emissions and regional transport to the atmosphere in Beijing during summer. PM2.5 samples collected with or without traffic restriction in Beijing are selected to evaluate the effectiveness of local traffic restriction measure on air pollution reduction. The average concentrations of the total quantified bifunctional organic compounds (TQBOC, total fatty acids and benzoic acid during the entire sampling period were 1184 ± 241 ng m−3, 597 ± 159 ng m−3 and 1496 ± 511ng m−3 in PKU, and 1050 ± 303 ng m−3, 475 ± 114 ng m−3 and 1278 ± 372 ng m−3 in Yufa. Oxalic acid (C2 was found as the most abundant dicarboxylic acid at PKU and Yufa, followed by phthalic acid (Ph. A strong even carbon number predominance with the highest level at palmitic acid (C16:0, followed by stearic acid (C18:0 was found for fatty acids. According to the back trajectories modeling results, the air masses were found to originate mainly from northeast, passing over southeast or south of Beijing (heavily populated, urbanized and industrialized areas, during heavier pollution events, whereas they are mainly from north or northwest sector (mountain areas without serious anthropogenic pollution sources during cleaner events. The data with wind only from the same sector (minimizing the difference from regional contribution but with and without traffic restriction in Beijing were analyzed to evaluate the effectiveness of local traffic restriction measure on the reduction of local air pollution in Beijing. The results

  16. Dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid in PM2.5 aerosol collected during CAREBeijing-2007: an effect of traffic restriction on air quality

    Science.gov (United States)

    Ho, K. F.; Huang, R.-J.; Kawamura, K.; Tachibana, E.; Lee, S. C.; Ho, S. S. H.; Zhu, T.; Tian, L.

    2015-03-01

    Thirty water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid were determined as well as organic carbon (OC), elemental carbon (EC) and water-soluble organic carbon (WSOC) in PM2.5 samples collected during the Campaign of Air Quality Research in Beijing 2007 (CAREBeijing-2007) in the urban and suburban areas of Beijing. The objective of this study is to identify the influence of traffic emissions and regional transport to the atmosphere in Beijing during summer. PM2.5 samples collected with or without traffic restriction in Beijing are selected to evaluate the effectiveness of local traffic restriction measures on air pollution reduction. The average concentrations of the total quantified bifunctional organic compounds (TQBOCs), total fatty acids and benzoic acid during the entire sampling period were 1184±241, 597±159 and 1496±511 ng m-3 in Peking University (PKU), and 1050±303, 475±114 and 1278±372 ng m-3 in Yufa, Beijing. Oxalic acid (C2) was found as the most abundant dicarboxylic acid at PKU and Yufa followed by phthalic acid (Ph). A strong even carbon number predominance with the highest level at stearic acid (C18:0), followed by palmitic acid (C16:0) was found for fatty acids. According to the back trajectories modeling results, the air masses were found to originate mainly from the northeast, passing over the southeast or south of Beijing (heavily populated, urbanized and industrialized areas), during heavier pollution events, whereas they are mainly from the north or northwest sector (mountain areas without serious anthropogenic pollution sources) during less pollution events. The data with wind only from the same sector (minimizing the difference from regional contribution) but with and without traffic restriction in Beijing were analyzed to evaluate the effectiveness of local traffic restriction measures on the reduction of local air pollution in Beijing. The results suggested

  17. Transcript and metabolite alterations increase ganoderic acid content in Ganoderma lucidum using acetic acid as an inducer.

    Science.gov (United States)

    Ren, Ang; Li, Xiong-Biao; Miao, Zhi-Gang; Shi, Liang; Jaing, Ai-Liang; Zhao, Ming-Wen

    2014-12-01

    Acetic acid at 5-8 mM increased ganoderic acid (GA) accumulation in Ganoderma lucidum. After optimization by the response surface methodology, the GA content reached 5.5/100 mg dry weight, an increase of 105% compared with the control. The intermediate metabolites of GA biosynthesis, lanosterol and squalene also increased to 47 and 15.8 μg/g dry weight, respectively, in response to acetic acid. Acetic acid significantly induced transcription levels of sqs, lano, hmgs and cyp51 in the GA biosynthesis pathway. An acetic acid-unregulated acetyl coenzyme A synthase (acs) gene was selected from ten candidate homologous acs genes. The results indicate that acetic acid alters the expression of genes related to acetic acid assimilation and increases GA biosynthesis and the metabolic levels of lanosterol, squalene and GA-a, thereby resulting in GA accumulation.

  18. Overexpression of acetyl-CoA synthetase in Saccharomyces cerevisiae increases acetic acid tolerance

    OpenAIRE

    Ding, Jun; Holzwarth, Garrett; Penner, Michael H.; Patton-Vogt, Jana; Bakalinsky, Alan T.

    2015-01-01

    Acetic acid-mediated inhibition of the fermentation of lignocellulose-derived sugars impedes development of plant biomass as a source of renewable ethanol. In order to overcome this inhibition, the capacity of Saccharomyces cerevisiae to synthesize acetyl-CoA from acetic acid was increased by overexpressing ACS2 encoding acetyl-coenzyme A synthetase. Overexpression of ACS2 resulted in higher resistance to acetic acid as measured by an increased growth rate and shorter lag phase relative to a ...

  19. Two di-alkyl-ammonium salts of 2-amino-4-nitro-benzoic acid: crystal structures and Hirshfeld surface analysis.

    Science.gov (United States)

    Wardell, James L; Jotani, Mukesh M; Tiekink, Edward R T

    2016-12-01

    The crystal structures of two ammonium salts of 2-amino-4-nitro-benzoic acid are described, namely di-methyl-aza-nium 2-amino-4-nitro-benzoate, C2H8N(+)·C7H5N2O4(-), (I), and di-butyl-aza-nium 2-amino-4-nitro-benzoate, C8H20N(+)·C7H5N2O4(-), (II). The asymmetric unit of (I) comprises a single cation and a single anion. In the anion, small twists are noted for the carboxyl-ate and nitro groups from the ring to which they are connected, as indicated by the dihedral angles of 11.45 (13) and 3.71 (15)°, respectively; the dihedral angle between the substituents is 7.9 (2)°. The asymmetric unit of (II) comprises two independent pairs of cations and anions. In the cations, different conformations are noted in the side chains in that three chains have an all-trans [(+)-anti-periplanar] conformation, while one has a distinctive kink resulting in a (+)-synclinal conformation. The anions, again, exhibit twists with the dihedral angles between the carboxyl-ate and nitro groups and the ring being 12.73 (6) and 4.30 (10)°, respectively, for the first anion and 8.1 (4) and 12.6 (3)°, respectively, for the second. The difference between anions in (I) and (II) is that in the anions of (II), the terminal groups are conrotatory, forming dihedral angles of 17.02 (8) and 19.0 (5)°, respectively. In each independent anion of (I) and (II), an intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is formed. In the crystal of (I), anions are linked into a jagged supra-molecular chain by charge-assisted amine-N-H⋯O(carboxyl-ate) hydrogen bonds and these are connected into layers via charge-assisted ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. The resulting layers stack along the a axis, being connected by nitro-N-O⋯π(arene) and methyl-C-H⋯O(nitro) inter-actions. In the crystal of (II), the anions are connected into four-ion aggregates by charge-assisted amino-N-H⋯O(carboxyl-ate) hydrogen bonding. The formation of ammonium

  20. Development of Acetic Acid Removal Technology for the UREX+Process

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Counce; Jack S. Watson

    2009-06-30

    It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

  1. Study of Effect of Variation of Ionic Strength of the Medium on Velocity Constant of Ru(Iii Catalyzed Oxidation of Hydroxy Benzoic Acids by Chloramine-T in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Dr. Parmod Kumar

    2014-01-01

    Full Text Available In the present study the effect of variation of ionic strength of the medium on rate of oxidation of hydroxy benzoic acids as its effect provides some clues regarding the nature of reactive species involved in the rate determining step. In order to realize the above aim the experiments has been carried out which ultimately concluded that ionic strength variation does not change the reaction velocity constant significantly.

  2. Acetic acid in aged vinegar affects molecular targets for thrombus disease management.

    Science.gov (United States)

    Jing, Li; Yanyan, Zhang; Junfeng, Fan

    2015-08-01

    To elucidate the mechanism underlying the action of dietary vinegar on antithrombotic activity, acetic acid, the main acidic component of dietary vinegar, was used to determine antiplatelet and fibrinolytic activity. The results revealed that acetic acid significantly inhibits adenosine diphosphate (ADP)-, collagen-, thrombin-, and arachidonic acid (AA)-induced platelet aggregation. Acetic acid (2.00 mM) reduced AA-induced platelet aggregation to approximately 36.82 ± 1.31%, and vinegar (0.12 mL L(-1)) reduced the platelet aggregation induced by AA to 30.25 ± 1.34%. Further studies revealed that acetic acid exerts its effects by inhibiting cyclooxygenase-1 and the formation of thromboxane-A2. Organic acids including acetic acid, formic acid, lactic acid, citric acid, and malic acid also showed fibrinolytic activity; specifically, the fibrinolytic activity of acetic acid amounted to 1.866 IU urokinase per mL. Acetic acid exerted its fibrinolytic activity by activating plasminogen during fibrin crossing, thus leading to crosslinked fibrin degradation by the activated plasmin. These results suggest that organic acids in dietary vinegar play important roles in the prevention and cure of cardiovascular diseases.

  3. Synthesis and characterization of acetic acid and ethanoic acid (based)-maleimide

    Science.gov (United States)

    Poad, Siti Nashwa Mohd; Hassan, Nurul Izzaty; Hassan, Nur Hasyareeda

    2016-11-01

    A new route to the synthesis of maleimide is described. 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)acetic acid maleimide (1) and 2-(4-(2,5-Dioxo-2,5-dihydro- 1H-pyrrol-1-yl)phenyl)ethanoic acid maleimide (2) have been synthesized by the reaction of maleic anhydride with glycine and 4-aminophenyl acetic aicd. Maleimide (1) was synthesized by conventional technique while maleimide (2) was synthesized by microwave method. The compounds were characterized using FT-Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopies and Mass Spectrometry.

  4. Synthesis, biological evaluation, and structure-activity relationships of 2-[2-(benzoylamino)benzoylamino]benzoic acid analogues as inhibitors of adenovirus replication.

    Science.gov (United States)

    Öberg, Christopher T; Strand, Mårten; Andersson, Emma K; Edlund, Karin; Tran, Nam Phuong Nguyen; Mei, Ya-Fang; Wadell, Göran; Elofsson, Mikael

    2012-04-12

    2-[2-Benzoylamino)benzoylamino]benzoic acid (1) was previously identified as a potent and nontoxic antiadenoviral compound (Antimicrob. Agents Chemother. 2010, 54, 3871). Here, the potency of 1 was improved over three generations of compounds. We found that the ortho, ortho substituent pattern and the presence of the carboxylic acid of 1 are favorable for this class of compounds and that the direction of the amide bonds (as in 1) is obligatory. Some variability in the N-terminal moiety was tolerated, but benzamides appear to be preferred. The substituents on the middle and C-terminal rings were varied, resulting in two potent inhibitors, 35g and 35j, with EC(50) = 0.6 μM and low cell toxicity.

  5. Crystal structure of 4-(3-carb-oxy-pro-pan-amido)-2-hy-droxy-benzoic acid mono-hydrate.

    Science.gov (United States)

    Tahir, Muhammad Nawaz; Ahmed, Muhammad Naeem; Butt, Arshad Farooq; Shad, Hazoor Ahmad

    2014-12-01

    In the title hydrate, C11H11NO6·H2O, the organic mol-ecule is approximately planar (r.m.s. deviation for the non-H atoms = 0.129 Å) and an intra-molecular O-H⋯O hydrogen bond closes an S(6) ring. In the crystal, the benzoic acid group participates in an O-H⋯O hydrogen bond to the water mol-ecule and accepts a similar bond from another water mol-ecule. The other -CO2H group forms a carb-oxy-lic acid inversion dimer, thereby forming an R 2 (2)(8) loop. These bonds, along with N-H⋯O and C-H⋯O inter-actions, generate a three-dimensional network.

  6. Synthesis and phase behavior of dendrons derived from 3,4,5-tris(tetradecyloxy)benzoic acid with different functional groups in focal point

    Indian Academy of Sciences (India)

    Matvey Gruzdev; Ulyana Chervonova; Olga Akopova; Arkadiy Kolker

    2015-10-01

    A number of dendrons of various chain lengths derived from the esters of 3,4,5-tris(tetrade-cyloxy)benzoic acid were synthesized. These esters were used as building blocks in the design of polyester molecules. Intermediate products, such as branched compounds with variation of functional groups in focal point (aromatic acids and their benzyl esters, aldehydes of different generation) were obtained. The structure and purity of all the compounds were determined by elemental analysis, FT-IR, NMR spectroscopy, mass spectrometry (MALDI-ToF). The phase behavior was investigated by differential scanning calorimetry and confirmed by polarized optical microscopy. Consequently, it was established that the liquid-crystalline properties of this series of dendrons arise from the degree of branching. This behavior can be explained by the formation of hydrogen bonds, as well as microsegregation processes of the links of the macromolecule.

  7. Enhanced biofuel production through coupled acetic acid and xylose consumption by engineered yeast

    National Research Council Canada - National Science Library

    Wei, Na; Quarterman, Josh; Kim, Soo Rin; Cate, Jamie H D; Jin, Yong-Su

    2013-01-01

    .... However, commercial production of cellulosic biofuel has been hampered by inefficient fermentation of xylose and the toxicity of acetic acid, which constitute substantial portions of cellulosic biomass...

  8. Leaching of spent lead acid battery paste components by sodium citrate and acetic acid.

    Science.gov (United States)

    Zhu, Xinfeng; He, Xiong; Yang, Jiakuan; Gao, Linxia; Liu, Jianwen; Yang, Danni; Sun, Xiaojuan; Zhang, Wei; Wang, Qin; Kumar, R Vasant

    2013-04-15

    A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting methods, is proposed for treating components of spent lead-acid battery pastes in aqueous organic acid(s). In this study, PbO, PbO2, and PbSO4, the three major components in a spent lead paste, were individually reacted with a mixture of aqueous sodium citrate and acetic acid solution. Pure lead citrate precursor of Pb3(C6H5O7)2 · 3H2O is the only product crystallized in each leaching experiment. Conditions were optimized for individual lead compounds which were then used as the basis for leaching real industrial spent paste. In this work, efficient leaching process is achieved and raw material cost is reduced by using aqueous sodium citrate and acetic acid, instead of aqueous sodium citrate and citric acid as reported in a pioneering hydrometallurgical method earlier. Acetic acid is not only cheaper than citric acid but is also more effective in aiding dissolution of the lead compounds thus speeding up the leaching process in comparison with citric acid. Lead citrate is readily crystallized from the aqueous solution due to its low solubility and can be combusted to directly produce leady oxide as a precursor for making new battery pastes.

  9. L-Lactic acid production from glycerol coupled with acetic acid metabolism by Enterococcus faecalis without carbon loss.

    Science.gov (United States)

    Murakami, Nao; Oba, Mana; Iwamoto, Mariko; Tashiro, Yukihiro; Noguchi, Takuya; Bonkohara, Kaori; Abdel-Rahman, Mohamed Ali; Zendo, Takeshi; Shimoda, Mitsuya; Sakai, Kenji; Sonomoto, Kenji

    2016-01-01

    Glycerol is a by-product in the biodiesel production process and considered as one of the prospective carbon sources for microbial fermentation including lactic acid fermentation, which has received considerable interest due to its potential application. Enterococcus faecalis isolated in our laboratory produced optically pure L-lactic acid from glycerol in the presence of acetic acid. Gas chromatography-mass spectrometry analysis using [1, 2-(13)C2] acetic acid proved that the E. faecalis strain QU 11 was capable of converting acetic acid to ethanol during lactic acid fermentation of glycerol. This indicated that strain QU 11 restored the redox balance by oxidizing excess NADH though acetic acid metabolism, during ethanol production, which resulted in lactic acid production from glycerol. The effects of pH control and substrate concentration on lactic acid fermentation were also investigated. Glycerol and acetic acid concentrations of 30 g/L and 10 g/L, respectively, were expected to be appropriate for lactic acid fermentation of glycerol by strain QU 11 at a pH of 6.5. Furthermore, fed-batch fermentation with 30 g/L glycerol and 10 g/L acetic acid wholly exhibited the best performance including lactic acid production (55.3 g/L), lactic acid yield (0.991 mol-lactic acid/mol-glycerol), total yield [1.08 mol-(lactic acid and ethanol)]/mol-(glycerol and acetic acid)], and total carbon yield [1.06 C-mol-(lactic acid and ethanol)/C-mol-(glycerol and acetic acid)] of lactic acid and ethanol. In summary, the strain QU 11 successfully produced lactic acid from glycerol with acetic acid metabolism, and an efficient fermentation system was established without carbon loss.

  10. Separation of Acetic Acid from Aqueous Solution using Various Organic Solvents

    Directory of Open Access Journals (Sweden)

    Md. Zaved Hossain Khan

    2014-01-01

    Full Text Available 800x600 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the study a model has been developed to separate the acetic acid from aqueous solution by liquid-liquid extraction and find out the proper solvent for this separation. Various solvents such as n-butanol, iso butanol, amyl alcohol and ethyl acetate are used for separation of acetic acid from water. The binodal curves (mutual solubility curves for acetic acid distributed between water and an organic solvent were obtained by titrating known mixtures of two components (water and solvents with the third component acetic acid to the point of first appearance of permanent turbidity. In order to determine the tie-lines, the absorbance of the coexisting phases, obtained by the separation of ternary mixtures within the binodal curve are needed to be determined. The absorbance of each point had been determined by a UV spectrophotometer. Distribution diagrams are obtained by plotting weight percent of acetic acid in solvent phase against the weight percent of acetic acid in water phase. Selectivity diagrams are also obtained by plotting (wt. % of acetic acid / (percent of acetic acid + percent of water in solvent phase against the same quantity in the diluent phase. The separation factor is determined numerically from the tie-line data.

  11. Effects of Oxygen Availability on Acetic Acid Tolerance and Intracellular pH in Dekkera bruxellensis.

    Science.gov (United States)

    Capusoni, Claudia; Arioli, Stefania; Zambelli, Paolo; Moktaduzzaman, M; Mora, Diego; Compagno, Concetta

    2016-08-01

    The yeast Dekkera bruxellensis, associated with wine and beer production, has recently received attention, because its high ethanol and acid tolerance enables it to compete with Saccharomyces cerevisiae in distilleries that produce fuel ethanol. We investigated how different cultivation conditions affect the acetic acid tolerance of D. bruxellensis We analyzed the ability of two strains (CBS 98 and CBS 4482) exhibiting different degrees of tolerance to grow in the presence of acetic acid under aerobic and oxygen-limited conditions. We found that the concomitant presence of acetic acid and oxygen had a negative effect on D. bruxellensis growth. In contrast, incubation under oxygen-limited conditions resulted in reproducible growth kinetics that exhibited a shorter adaptive phase and higher growth rates than those with cultivation under aerobic conditions. This positive effect was more pronounced in CBS 98, the more-sensitive strain. Cultivation of CBS 98 cells under oxygen-limited conditions improved their ability to restore their intracellular pH upon acetic acid exposure and to reduce the oxidative damage to intracellular macromolecules caused by the presence of acetic acid. This study reveals an important role of oxidative stress in acetic acid tolerance in D. bruxellensis, indicating that reduced oxygen availability can protect against the damage caused by the presence of acetic acid. This aspect is important for optimizing industrial processes performed in the presence of acetic acid. This study reveals an important role of oxidative stress in acetic acid tolerance in D. bruxellensis, indicating that reduced oxygen availability can have a protective role against the damage caused by the presence of acetic acid. This aspect is important for the optimization of industrial processes performed in the presence of acetic acid. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  12. [Physiological response to acetic acid stress of Acetobacter pasteuranus during vinegar fermentation].

    Science.gov (United States)

    Qi, Zhengliang; Yang, Hailin; Xia, Xiaole; Wang, Wu; Leng, Yunwei; Yu, Xiaobin; Quan, Wu

    2014-03-04

    The aim of the study is to propose a dynamic acetic acid resistance mechanism through analysis on response of cellular morphology, physiology and metabolism of A. pasteurianus CICIM B7003 during vinegar fermentation. Vinegar fermentation was carried out in a Frings 9 L acetator by strain B7003 and cultures were sampled at different cellular growth phases. Simultaneously, percentage of capsular polysaccharide versus dry cells weight, ratio of unsaturated fatty acids to saturated fatty acids, transcription of acetic acid resistance genes, activity of alcohol respiratory chain enzymes and ATPase were detected for these samples to assay the responses of bacterial morphology, physiology and metabolism. When acetic acid was existed, no obvious capsular polysaccharide was secreted by cells. As vinegar fermentation proceeding, percentage of capsular polysaccharide versus dry cells weight was reduced from 2.5% to 0.89%. Ratio of unsaturated fatty acids to saturated fatty acids was increased obviously which can improve membrane fluidity. Also transcription level of acetic acid resistance genes was promoted. Interestingly, activity of alcohol respiratory chain and ATPase was not inhibited but promoted obviously with acetic acid accumulation which could provide enough energy for acetic acid resistance mechanism. On the basis of the results obtained from the experiment, A. pasteurianus CICIM B7003 relies mainly on the cooperation of changes of extracellular capsular polysaccharide and membrane fatty acids, activation of acid resistance genes transcription, enhancement of activity of alcohol respiratory chain and rapid energy production to tolerate acidic environment.

  13. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods

    Directory of Open Access Journals (Sweden)

    K Beheshti-Maal

    2010-06-01

    Full Text Available Background and Objectives: Acetic acid bacteria (AAB are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition."nResults: Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03% was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number # GU059865. The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12oC for more than a month. Longer preservation was possible at -70oC."nConclusion: The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

  14. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods.

    Science.gov (United States)

    Sharafi, Sm; Rasooli, I; Beheshti-Maal, K

    2010-03-01

    Acetic acid bacteria (AAB) are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity. Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC) medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition. Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03%) was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number#GU059865). The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12°C for more than a month. Longer preservation was possible at -70°C. The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

  15. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Pingping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Li, Jie [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Bu, Huaiyu, E-mail: 7213792@qq.com [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Wei, Qing [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Zhang, Ruolin [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Chen, Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu{sub 0.5}L]{sub n} (1), [Cu(HL){sub 2}Cl{sub 2}]{sub n} (2), [Cu(HL){sub 2}Cl{sub 2}(H{sub 2}O)] (3), [Cu(L){sub 2}(H{sub 2}O)]{sub n} (4) and [Cu(L)(phen)(HCO{sub 2})]{sub n} (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl{sup -}, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units –Cu–O–Cu–O– are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated. - Graphical abstract: Copper(II) compounds with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid, were prepared, structurally characterized and investigated for antifungal activity. - Highlights: • The title compounds formed by thermodynamics and thermokinetics. • The five compounds show higher inhibition percentage than reactants. • The structure effect on the antifungal activity.

  16. Simultaneous Determination of Benzoic Acid and Salicylic Acid in Compound Benz oic Acid Ointment by K-Factor UV Spectrophotometry%系数倍率紫外光谱法同时测定复方苯甲酸软膏中的苯甲酸和水杨酸的研究

    Institute of Scientific and Technical Information of China (English)

    吴咏梅; 叶芝祥; 蔡铎昌

    2001-01-01

    本文用系数倍率紫外光谱法同时测定了复方苯甲酸软膏中苯甲酸和水杨酸的含量,取得了满意的结果,苯甲酸测定回收率为99.33%—101.80%,水杨酸测定回收率为100.92%—105.46%。%The contents of benzoic acid and salicylic acid in compound benzoic acid ointment were simultaneously determined by K-factor UV spectrophotometry. The resu lt is satisfactory. The recoveries of benzoic acid and salicylic acid are in the range of 99.33%—101.80% and 100.92%—105.46%,respectively.

  17. Indole-3-acetic acid metabolism in normal and dwarf micropropagated banana plants (Musa spp. AAA)

    OpenAIRE

    Zaffari,Gilmar Roberto; Peres,Lázaro Eustáquio Pereira; Tcacenco,Fernando Adami; Kerbauy,Gilberto Barbante

    2002-01-01

    Nanism is one of the most frequent type of mutant in micropropagated banana plants from the Cavendish subgroup. The present study aimed at studying some of the hormone factors involved in this type of mutation. Rhizomes from normal and dwarf plants from the cultivar Grand Naine were incubated for 5 d in the presence of [³H]-L-tryptophan, [³H]-indole-3-acetic acid and gibberellin, to quantify the endogenous levels of indole-3-acetic acid-ester, indole-3-acetic acid-amide, free indole-3-acetic ...

  18. [Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].

    Science.gov (United States)

    Zhao, Xinqing; Zhang, Mingming; Xu, Guihong; Xu, Jianren; Bai, Fengwu

    2014-03-01

    Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.

  19. Enhanced expression of aconitase raises acetic acid resistance in Acetobacter aceti.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

    2004-06-15

    Acetobacter spp. are used for industrial vinegar production because of their high ability to oxidize ethanol to acetic acid and high resistance to acetic acid. Two-dimensional gel electrophoretic analysis of a soluble fraction of Acetobacter aceti revealed the presence of several proteins whose production was enhanced, to various extents, in response to acetic acid in the medium. A protein with an apparent molecular mass of 100 kDa was significantly enhanced in amount by acetic acid and identified to be aconitase by NH2-terminal amino acid sequencing and subsequent gene cloning. Amplification of the aconitase gene by use of a multicopy plasmid in A. aceti enhanced the enzymatic activity and acetic acid resistance. These results showed that aconitase is concerned with acetic acid resistance. Enhancement of the aconitase activity turned out to be practically useful for acetic acid fermentation, because the A. aceti transformant harboring multiple copies of the aconitase gene produced a higher concentration of acetic acid with a reduced growth lag-time.

  20. Atmospheric geochemistry of formic and acetic acids at a mid-latitude temperate site

    Science.gov (United States)

    Talbot, R. W.; Beecher, K. M.; Harriss, R. C.; Cofer, R. W., III

    1988-01-01

    Tropospheric concentrations of formic and acetic acids in the gas, the aerosol, and the rainwater phases were determined in samples collected 1-2 m above ground level at an open field site in eastern Virginia. These acids were found to occur principally (98 percent or above) in the gas phase, with a marked annual seasonality, averaging 1890 ppt for formate and 1310 ppt for acetate during the growing season, as compared to 695 ppt and 700 ppt, respectively, over the nongrowing season. The data support the hypothesis that biogenic emissions from vegatation are important sources of atmospheric formic and acetic acid during the local growing season. The same time trends were observed for precipitation, although with less defined seasonality. The relative increase of the acetic acid/formic acid ratio during the nongrowing season points to the dominance of anthropogenic inputs of acetic acid from motor vehicles and biomass combustion in the wintertime.

  1. Deletion of JJJ1 improves acetic acid tolerance and bioethanol fermentation performance of Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Wu, Xuechang; Zhang, Lijie; Jin, Xinna; Fang, Yahong; Zhang, Ke; Qi, Lei; Zheng, Daoqiong

    2016-07-01

    To improve tolerance to acetic acid that is present in lignocellulosic hydrolysates and affects bioethanol production by Saccharomyces cerevisiae. Saccharomyces cerevisiae strains with improved tolerance to acetic acid were obtained through deletion of the JJJ1 gene. The lag phase of the JJJ1 deletion mutant BYΔJJJ1 was ~16 h shorter than that of the parent strain, BY4741, when the fermentation medium contained 4.5 g acetic acid/l. Additionally, the specific ethanol production rate of BYΔJJJ1 was increased (0.057 g/g h) compared to that of the parent strain (0.051 g/g h). Comparative transcription and physiological analyses revealed higher long chain fatty acid, trehalose, and catalase contents might be critical factors responsible for the acetic acid resistance of JJJ1 knockout strains. JJJ1 deletion improves acetic acid tolerance and ethanol fermentation performance of S. cerevisiae.

  2. Progress in Acetic Acid Industry%醋酸工业现状及发展

    Institute of Scientific and Technical Information of China (English)

    李好管; 闫慧芳

    2001-01-01

    醋酸是用途最广泛的有机酸之一。分析了醋酸的生产和消费趋势;综述了醋酸工艺的进展;介绍了具有工业化前景或学术价值的醋酸合成新工艺的研究开发概况。对我国醋酸工业发展提出了建议。%Acetic acid is one of the organic acids which have many uses.This paper analyzed the production and consumption of acetic acid,summarized the progress of acetic acid technology,introduced the research and development of acetic acid new process.Some suggestions on China's acetic acid industry were also put forward.

  3. Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.

    Science.gov (United States)

    Hocking, M. B.

    1980-01-01

    Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)

  4. Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

    Science.gov (United States)

    Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

    2014-10-01

    The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

  5. 4-[3,5-Bis(2-hydroxyphenyl-1H-1,2,4-triazol-1-yl]benzoic acid dimethylformamide monosolvate

    Directory of Open Access Journals (Sweden)

    H. S. Yathirajan

    2012-03-01

    Full Text Available In the molecule of deferasirox dimethylformamide solvate, C21H15N3O4·C3H7NO, the central 1,2,4-triazole ring is tilted with respect to the benzoic acid and one of the 2-hydroxyphenyl units but coplanar with the other 2-hydroxyphenyl group, as indicated by the dihedral angles of 33.69 (9, 72.57 (8 and 5.18 (9°, respectively. Intramolecular O—H...N hydrogen bonds generate an S(6 ring motif. In the crystal, deferasirox molecules are linked by O—H...N hydrogen bonds and weak C—H...O interactions into chains along the c axis. The dimethylformamide solvent molecules are located between the deferasirox chains and are linked to the deferasirox molecules by O—H...O hydrogen bonds and weak C—H...O interactions.

  6. Photoinduced intramolecular charge-transfer reactions in 4-amino-3-methyl benzoic acid methyl ester: A fluorescence study in condensedphase and jet-cooled molecular beams

    Indian Academy of Sciences (India)

    Amrita Chakraborty; Samiran Kar; D N Nath; Nikhil Guchhait

    2007-03-01

    Photoinduced intramolecular charge-transfer reactions in 4-amino-3-methyl benzoic acid methyl ester (AMBME) have been investigated spectroscopically. AMBME, with its weak charge donor primary amino group, shows dual emission in polar solvents. Absorption and emission measurements in the condensed phase support the premise that the short wavelength emission band corresponds to local emission and the long wavelength emission band to the charge transfer emission. Laser-induced fluorescence excitation spectra show the presence of two low-energy conformers in jet-cooled molecular beams. Theoretical calculations using density functional theory help to determine structure, vibrational modes, potential energy surface, transition energy and oscillator strength for correlating experimental findings with theoretical results.

  7. Lead(II) coordination polymers based on rigid-flexible 3,5-bis-oxyacetate-benzoic acid: Structural transition driven by temperature control

    Science.gov (United States)

    Chen, Yong-Qiang; Tian, Yuan

    2017-03-01

    Three Pb(II) complexes {[Pb3(BOABA)2(H2O)]·H2O}n (1), {[Pb4(BOABA)2(μ4-O)(H2O)2]·H2O}n (2), and [Pb3(BOABA)2(H2O)]n (3) (H3BOABA=3,5-bis-oxyacetate-benzoic acid) were obtained under the same reaction systems with different temperatures. Complexes 1 and 2 are two dimensional (2D) networks based on Pb-BOABA chains and Pb4(μ4-O)(COO)6 SBUs, respectively. Complex 3 presents an interesting three dimensional (3D) framework, was obtained by increasing the reaction temperature. Structural transition of the crystallization products is largely dependent on the reaction temperature. Moreover, the fluorescence properties of complexes 1-3 have been investigated.

  8. A neutron diffraction study from 6 to 293 K and a macroscopic-scale quantum theory of the hydrogen bonded dimers in the crystal of benzoic acid

    CERN Document Server

    Fillaux, François

    2011-01-01

    The crystal of benzoic acid is comprised of tautomeric centrosymmetric dimers linked through bistable hydrogen bonds. Statistical disorder of the bonding protons is excluded by neutron diffraction from 6 K to 293 K. In addition to diffraction data, vibrational spectra and relaxation rates measured with solid-state-NMR and quasi-elastic neutron scattering are consistent with wave-like, rather than particle-like protons. We present a macroscopic-scale quantum theory for the bonding protons represented by a periodic lattice of fermions. The adiabatic separation, the exclusion principle, and the antisymmetry postulate yield a static lattice-state immune to decoherence. According to the theory of quantum measurements, vibrational spectroscopy and relaxometry involve realizations of decoherence-free Bloch states for nonlocal symmetry species that did not exist before the measurement. The eigen states are fully determined by three temperature-independent parameters which are effectively measured: the energy differen...

  9. Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid

    Directory of Open Access Journals (Sweden)

    Sá-Correia Isabel

    2010-10-01

    Full Text Available Abstract Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5. Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to

  10. Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid

    Science.gov (United States)

    2010-01-01

    Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5). Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are

  11. Effect of salt addition on acid resistance response of Escherichia coli O157:H7 against acetic acid.

    Science.gov (United States)

    Bae, Young-Min; Lee, Sun-Young

    2017-08-01

    A combination of salt and acid is commonly used in the production of many foods, such as pickles and fermented foods. However, in our previous studies, addition of salt significantly reduced the inhibitory effect of acetic acid against E. coli O157:H7 in laboratory media and pickled cucumbers. Therefore, this study was conducted to determine the effect of salt addition on the acid resistance (AR) response of E. coli O157:H7 after treatment with acetic acid. The combined effect of acetic acid and salt showed different results depending on media tested. Organic compounds such as yeast extract and tryptone were required to observe the antagonistic effect of salt and acetic acid in combination. However, use of an rpoS mutant or addition of chloramphenicol resulted in no changes in the antagonistic effect of acetic acid and salt. The addition of glutamate to phosphate buffer significantly increased the survival levels of E. coli O157:H7 after the acetic acid treatment; however, the survival levels were lower than those after the treatment with acetic acid alone. Thus, the addition of salt may increase the AR response of E. coli O157:H7; however, these survival mechanisms were not proven clearly. Therefore, further studies need to be performed to better understand the antagonism of acetic acid salt against E. coli O157:H7. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Electron attachment and electron ionization of acetic acid clusters embedded in helium nanodroplets

    NARCIS (Netherlands)

    da Silva, F. Ferreira; Jaksch, S.; Martins, G.; Dang, H. M.; Dampc, M.; Denifl, S.; Maerk, T. D.; Limao-Vieira, P.; Liu, J.; Yang, S.; Ellis, A. M.; Scheier, P.

    2009-01-01

    The effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic products ejected into the gas phase are detected by mass spectrometry. The cation chemistry (induced by electro

  13. Microbiological preservation of cucumbers for bulk storage by the use of acetic acid and food preservatives

    Science.gov (United States)

    Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to assure preservation were low en...

  14. Cervical cancer risk factors and feasibility of visual inspection with acetic acid screening in Sudan

    DEFF Research Database (Denmark)

    Ibrahim, Ahmed; Rasch, Vibeke; Pukkala, Eero;

    2011-01-01

    To assess the risk factors of cervical cancer and the feasibility and acceptability of a visual inspection with acetic acid (VIA) screening method in a primary health center in Khartoum, Sudan.......To assess the risk factors of cervical cancer and the feasibility and acceptability of a visual inspection with acetic acid (VIA) screening method in a primary health center in Khartoum, Sudan....

  15. Efficacy of Acetic Acid against Listeria monocytogenes Attached to Poultry Skin during Refrigerated Storage.

    Science.gov (United States)

    Gonzalez-Fandos, Elena; Herrera, Barbara

    2014-09-11

    This work evaluates the effect of acetic acid dipping on the growth of L. monocytogenes on poultry legs stored at 4 °C for eight days. Fresh inoculated chicken legs were dipped into either a 1% or 2% acetic acid solution (v/v) or distilled water (control). Changes in mesophiles, psychrotrophs, Enterobacteriaceae counts and sensorial characteristics (odor, color, texture and overall appearance) were also evaluated. The shelf life of the samples washed with acetic acid was extended by at least two days over the control samples washed with distilled water. L. monocytogenes counts before decontamination were 5.57 log UFC/g, and after treatment with 2% acetic acid (Day 0), L. monocytogenes counts were 4.47 log UFC/g. Legs washed with 2% acetic acid showed a significant (p acetic acid. This study demonstrates that while acetic acid did reduce populations of L. monocytogenes on meat, it did not completely inactivate the pathogen. The application of acetic acid may be used as an additional hurdle contributing to extend the shelf life of raw poultry and reducing populations of L. monocytogenes.

  16. A Binary Host Plant Volatile Lure Combined With Acetic Acid to Monitor Codling Moth (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Knight, A L; Basoalto, E; Katalin, J; El-Sayed, A M

    2015-10-01

    Field studies were conducted in the United States, Hungary, and New Zealand to evaluate the effectiveness of septa lures loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E)-4,8-dimethyl-1,3,7-nonatriene (nonatriene) alone and in combination with an acetic acid co-lure for both sexes of codling moth, Cydia pomonella (L.). Additional studies were conducted to evaluate these host plant volatiles and acetic acid in combination with the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone). Traps baited with pear ester/nonatriene + acetic acid placed within orchards treated either with codlemone dispensers or left untreated caught significantly more males, females, and total moths than similar traps baited with pear ester + acetic acid in some assays. Similarly, traps baited with codlemone/pear ester/nonatriene + acetic acid caught significantly greater numbers of moths than traps with codlemone/pear ester + acetic acid lures in some assays in orchards treated with combinational dispensers (dispensers loaded with codlemone/pear ester). These data suggest that monitoring of codling moth can be marginally improved in orchards under variable management plans using a binary host plant volatile lure in combination with codlemone and acetic acid. These results are likely to be most significant in orchards treated with combinational dispensers. Significant increases in the catch of female codling moths in traps with the binary host plant volatile blend plus acetic acid should be useful in developing more effective mass trapping strategies.

  17. Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-01-01

    Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min with the acetic acid concentrations between 0 and 400 g/kg RCS. After pretreatment, the liquor fractions and water-insoluble solids (WIS) were collected separately...

  18. Sustainable hydrogen from bio-oil - Steam reforming of acetic acid as a model oxygenate

    NARCIS (Netherlands)

    Takanabe, K.; Takanabe, Kazuhiro; Aika, Ken-ichi; Seshan, Kulathuiyer; Lefferts, Leonardus

    2004-01-01

    Steam reforming of acetic acid over Pt/ZrO2 catalysts has been investigated. Pt/ZrO2 catalysts are very active, completely converting acetic acid, and give a hydrogen yield close to thermodynamic equilibrium. The catalyst deactivated by formation of oligomers which block the active sites. The

  19. Equilibria of ternary system acetic acid-water-CO2 under subcritical conditions

    DEFF Research Database (Denmark)

    Gutierrez, Jose M. Jimenez; Mussatto, Solange I.; Tsou, Joana

    , such as acetic acid in fermentations [2, 3]. Thus, from a biotechnological perspective, it is highly interesting to research on the system CO2—H2O with different concentrations of acetic acid (HAc). Based on previous studies [4, 5], this project aims to investigate the vapour/liquid equilibria (VLE...

  20. Fabrication of First Chinese Made Reactor for Oxosvnthesis of Acetic Acid in Xi'an

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The first set of Chinese made reactor for oxo-synthesis of acetic acid has been fabricated by the Xi'an Nuclear Equipment Company,Ltd.This reactor has been transported to the site of equipment installation at the acetic acid production project owned by Shandong Yimeng Company,Ltd.,which has shattered the long-time precedent of relying upon imported equipment.

  1. Development and validation of an HPLC-DAD method for simultaneous determination of cocaine, benzoic acid, benzoylecgonine and the main adulterants found in products based on cocaine.

    Science.gov (United States)

    Floriani, Gisele; Gasparetto, João Cleverson; Pontarolo, Roberto; Gonçalves, Alan Guilherme

    2014-02-01

    Here, an HPLC-DAD method was developed and validated for simultaneous determination of cocaine, two cocaine degradation products (benzoylecgonine and benzoic acid), and the main adulterants found in products based on cocaine (caffeine, lidocaine, phenacetin, benzocaine and diltiazem). The new method was developed and validated using an XBridge C18 4.6mm×250mm, 5μm particle size column maintained at 60°C. The mobile phase consisted of a gradient of acetonitrile and ammonium formate 0.05M - pH 3.1, eluted at 1.0mL/min. The volume of injection was 10μL and the DAD detector was set at 274nm. Method validation assays demonstrated suitable sensitivity, selectivity, linearity, precision and accuracy. For selectivity assay, a MS detection system could be directly adapted to the method without the need of any change in the chromatographic conditions. The robustness study indicated that the flow rate, temperature and pH of the mobile phase are critical parameters and should not be changed considering the conditions herein determined. The new method was then successfully applied for determining cocaine, benzoylecgonine, benzoic acid, caffeine, lidocaine, phenacetin, benzocaine and diltiazem in 115 samples, seized in Brazil (2007-2012), which consisted of cocaine paste, cocaine base and salt cocaine samples. This study revealed cocaine contents that ranged from undetectable to 97.2%, with 97 samples presenting at least one of the degradation products or adulterants here evaluated. All of the studied degradation products and adulterants were observed among the seized samples, justifying the application of the method, which can be used as a screening and quantification tool in forensic analysis.

  2. 肉桂等3种挥发油对苯甲酸透皮吸收的影响%The influence of Cinnamon oil and other volatile oils on percutaneous absorption of benzoic acid

    Institute of Scientific and Technical Information of China (English)

    沈琦; 胡晋红; 徐莲英

    2001-01-01

    OBJECTIVE To study the effect of Cinnamon oil, Eugenia oil andGalangal oil on the percutaneous penetration of benzoic acid. METHODS In order to compare the effect of the volatile oils and in combination with ethanol and propylene glycol on percutaneous penetration, the cumulative amount of benzoic acid penetrated through the skin was determined in vitro with Valia-Chien horizontal diffusion cell and HPLC.RESULTS All of the volatile oils enhanced remarkably the skin penetration of benzoic acid,and these volatile oils in combination with ethanol and propylene glycol increased the cummulative amount of benzoic acid,but decreased permeability coefficients.CONCLUSIONS Cinnamon oil, Eugenia oil and Galangal oil can be used to enhance the percutaneous absorption of benzoic acid.%目的:研究肉桂油、高良姜油、丁香油对苯甲酸透皮吸收的影响。方法:采用体外透皮双室扩散池和HPLC法,测定模型药物苯甲酸的累积渗透量,以考察不同浓度的肉桂油、高良姜油、丁香油对苯甲酸的促渗效果及挥发油与乙醇、丙二醇合用后的情况。结果:肉桂油、丁香油、丁香酚、高良姜油对苯甲酸均具有一定的促渗作用,挥发油与乙醇、丙二醇合用,使苯甲酸的累积渗透量增大,但渗透系数减小。结论:肉桂油、高良姜油、丁香油等能促进苯甲酸的透皮吸收。

  3. Acetate/acetyl-CoA metabolism associated with cancer fatty acid synthesis: overview and application.

    Science.gov (United States)

    Yoshii, Yukie; Furukawa, Takako; Saga, Tsuneo; Fujibayashi, Yasuhisa

    2015-01-28

    Understanding cancer-specific metabolism is important for identifying novel targets for cancer diagnosis and therapy. Induced acetate/acetyl CoA metabolism is a notable feature that is related to fatty acid synthesis supporting tumor growth. In this review, we focused on the recent findings related to cancer acetate/acetyl CoA metabolism. We also introduce [1-¹¹C]acetate positron emission tomography (PET), which is a useful tool to visualize up-regulation of acetate/acetyl CoA metabolism in cancer, and discuss the utility of [1-¹¹C]acetate PET in cancer diagnosis and its application to personalized medicine.

  4. The key to acetate: metabolic fluxes of acetic acid bacteria under cocoa pulp fermentation-simulating conditions.

    Science.gov (United States)

    Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik; Wittmann, Christoph

    2014-08-01

    Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.

  5. Recovery of Dilute Acetic Acid by Catalytic Distillation Using NKC-9 as Catalyst

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhigang; LI Xiaofeng; XU Shimin; LI Xingang

    2006-01-01

    The reaction kinetics of dilute acetic acid with methanol using NKC-9 as catalyst was studied at temperatures of 308 K, 318 K, 323 K, 328 K. The kinetic model based on Langmuir-Hinshelwood rate model was derived and the activation energy was 6.13 x 104 kJ/kmol. The experiment of recovery of dilute acetic acid was conducted in a packed bed catalytic distillation column. The optimal process parameters and operational conditions determined to make up to 85.9% conversion of acetic acid are as follows:the height of catalyst bed is 1 100 mm, reflux ratio is 4: 1, and the ratio of methanol to acetic acid is 2: 1. The method can be used as a guide in industrial scale recovery of 15%-30% dilute acetic acid.

  6. Reducing ulcerogenic potential of biphenyl acetic acid: Design and development of chimeric derivatives with amino acids

    Directory of Open Access Journals (Sweden)

    Suneela Dhaneshwar

    2016-09-01

    Full Text Available In an attempt to minimize the ulcerogenic potential and associated gastro-intestinal toxicity of bioprecursor fenbufen and its active metabolite biphenyl acetic acid, carrier-linked chimeric derivatives of the latter were designed and synthesized using amino acids as the promoities. DCC coupling method was used for the synthesis of these amides. The chimeras were characterized by IR and 1H NMR. Pharmacological investigations were carried out in animal models for analgesic, anti-inflammatory, anti-arthritic and ulcerogenic activities. The chimeras exhibited high gastro-sparing effect; quick onset and longer duration of analgesia; enhanced/prolonged anti-inflammatory activity and better anti-arthritic effect than fenbufen or biphenyl acetic acid. These derivatives could be useful as a chronotherapy for rheumatoid arthritis due to their prolonged analgesic and anti-inflammatory effects.

  7. Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid.

    Science.gov (United States)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-02-23

    Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 degrees C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic and lactic acid. Glucan recovery was less sensitive to the pretreatment conditions than xylan recovery. The pretreatment with acetic and lactic acid yielded the highest glucan recovery of 95.66%. The glucan recoveries of the other three pretreatments varied between 83.92% and 94.28%. Fermentability tests were performed on liquors obtained from all pretreatments and there were no inhibition effect found in any of the liquors. Simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) showed that a high ethanol yield of 88.7% of the theoretical based on glucose in the raw material was obtained following pretreatment at 195 degrees C for 15 min with acetic acid employed. The estimated total ethanol production was 241.1 kg/ton raw material by assuming fermentation of both C-6 and C-5, and 0.51 g ethanol/g sugar.

  8. Effects of pH and acetic acid on homoacetic fermentation of lactate by Clostridium formicoaceticum.

    Science.gov (United States)

    Tang, I C; Okos, M R; Yang, S T

    1989-10-20

    Clostridium formicoaceticum homofermentatively converts lactate to acetate at 37 degrees C and pH 6.6-9.6. However, this fermentation is strongly inhibited by acetic acid at acidic pH. The specific growth rate of this organism decreased from a maximum at pH 7.6 to zero at pH 6.6. This inhibition effect was found to be attributed to both H(+) and undissociated acetic acid. At pH values below 7.6, the H(+) inhibited the fermentation following non-competitive inhibition kinetics. The acetic acid inhibition was found to be stronger at a lower medium pH. At pH 6.45-6.8, cell growth was found to be primarily limited by a maximum undissociated acetic acid concentration of 0.358 g/L (6mM). This indicates that the undissociated acid, not the dissociated acid, is the major acid inhibitor. At pH 7.6 or higher, this organism could tolerate acetate concentrations of higher than 0.8M, but salt (Na(+)) became a strong inhibitor at concentrations of higher than 0.4M. Acetic acid inhibition also can be represented by noncompetitive inhibition kinetics. A mathematical model for this homoacetic fermentation was also developed. This model can be used to simulate batch fermentation at any pH between 6.9 and 7.6.

  9. Metabolic regulation of the plant hormone indole-3-acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jerry D. Cohen

    2009-11-01

    The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

  10. Evaluation of the morphological changes of gastric mucosa induced by a low concentration of acetic acid using a rat model.

    Science.gov (United States)

    Nakao, Ken-ichiro; Ro, Ayako; Kibayashi, Kazuhiko

    2014-02-01

    Oral ingestion of concentrated acetic acid causes corrosive injury of the gastrointestinal tract. To assess the effects of a low concentration of acetic acid on gastric mucosa, we examined the gastric mucosal changes in rats at 1 and 3 days after the injection of 5% or 25% acetic acid into the gastric lumen. The area of the gastric ulcerative lesions in the 25% acetic acid group was significantly larger than that in the 5% acetic acid group. The lesion area was reduced significantly at 3 days after injection in the 5% acetic acid group, whereas no significant difference in lesion area was observed at 1 and 3 days in the 25% acetic acid group. Histologically, corrosive necrosis was limited to the mucosal layer in the 5% acetic acid group, whereas necrosis extended throughout the gastric wall in the 25% acetic acid group. At 3 days post-injection, the 25% acetic acid group showed widespread persistent inflammation, whereas the 5% acetic acid group showed widespread appearance of fibroblasts indicative of a healing process. These results indicate that a low concentration of acetic acid damages the gastric mucosa and that the degree of mucosal damage depends on the concentration of acetic acid.

  11. Absorption mechanism study of benzoic acid on calcite. Influence on the wettability; Etude du mecanisme d`absorption de l`acide benzoique sur la calcite. Incidence sur la mouillabilite

    Energy Technology Data Exchange (ETDEWEB)

    Legens, Ch.

    1997-12-03

    A pure carbonate rock is strongly water-wet whereas oil accumulations study shows that most of carbonate reservoirs are oil-wet or of mixed-wettability. This is one of the main difficulties to extract crude oil. This change of behavior is due to the adsorption of some crude oil compounds on the mineral surface. We have mainly studied the interactions between acid molecules by adsorption on a calcite powder in an organic phase (benzoic acid and lauric acid) and in an aqueous phase (benzoic acid and lauric sodium salt). The technics which enabled us to define and characterize adsorption are thermogravimetry infrared diffuse reflection and thermal analysis with controlled kinetic linked to a mass spectrometer. Molecular modelling calculations have completed these analysis. It has been showed that when crude oil fills the biggest pores of the reservoir rock, the aqueous film is unstable and acids adsorb via ionic bonds on mineral calcium ions. Wettability is evaluated thanks to contact angle measurements of a water droplet deposited on a compacted powder pellet. Calcite wettability changes were all the greater as hydro-carbonated chains were longer, as it confers molecule hydrophobia. It has been also investigated acid molecules diffusion from the organic to the aqueous phase which saturates the smallest pores. Molecules which are able to diffuse from the first to the second medium do not adsorb on the surface. As a consequence, carbonate rock wettability changes require a direct contact between crude oil and mineral that involves aqueous film instability. (author) 128 refs.

  12. Experimental Measurements and Correlations Isobaric Vapor-Liquid Equilibria for Water + Acetic Acid + Sec-butyl Acetate at 101.3 kPa

    Institute of Scientific and Technical Information of China (English)

    LI Ling; HE Yong; WU Yanxiang; ZOU Wenhu

    2013-01-01

    Isobaric vapor-liquid equilibrium(VLE) data for acetic acid + sec-butyl acetate and water + acetic acid + sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type.The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O'Connell method.Thermodynamic consistency was tested for the binary VLE data.The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model.The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038.The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells.The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation.The binary interaction parameters and the ternary VLE data were obtained from this work.

  13. Effect of acetic acid on rice seeds coated with rice husk ash

    OpenAIRE

    Lizandro Ciciliano Tavares; André Pich Brunes; Daniel Andrei Robe da Fonseca; Gizele Ingrid Gadotti; Lilian Madruga de Tunes; Géri Eduardo Meneghello; Antonio Carlos Souza Albuquerque Barros

    2013-01-01

    Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência), five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed) and five concentrations of acetic acid (0, 3,...

  14. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    António Rego

    2014-08-01

    Full Text Available Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria.

  15. Effect of roxatidine acetate on daytime and night-time peptone-stimulated gastric acid secretion.

    Science.gov (United States)

    Hagenmüller, F

    1988-01-01

    A double-blind, randomised, crossover study in 12 healthy volunteers was performed to assess the effects of roxatidine acetate 75 mg or placebo administered at 8 am and 9 pm on peptone-stimulated hydrochloric acid secretion. In comparison to placebo, roxatidine acetate produced an average reduction of daytime hydrochloric acid output of 86% and 32%, respectively, for the 4- to 6-hour and 10- to 12-hour post-drug administration phases. In addition, roxatidine acetate produced reductions in nocturnal hydrochloric acid output of 75 to 92% with an associated rise in intragastric pH of around 2 units compared to placebo. No side effects or clinically significant alterations in haematological or biochemical values were reported following roxatidine acetate administration. These results suggest that roxatidine acetate is a potent and effective inhibitor of day and night-time intragastric acid secretion.

  16. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    Science.gov (United States)

    Rego, António; Duarte, Ana M.; Azevedo, Flávio; Sousa, Maria J.; Côrte-Real, Manuela; Chaves, Susana R.

    2014-01-01

    Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria. PMID:28357256

  17. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4

  18. Beneficial Effect of Acetic Acid on the Xylose Utilization and Bacterial Cellulose Production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Yang, Xiao-Yan; Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Luo, Jun; Wang, Bo; Chen, Xue-Fang; Lin, Xiao-Qing; Chen, Xin-De

    2014-09-01

    In this work, acetic acid was found as one promising substrate to improve xylose utilization by Gluconacetobacter xylinus CH001. Also, with the help of adding acetic acid into medium, the bacterial cellulose (BC) production by G. xylinus was increased significantly. In the medium containing 3 g l(-1) acetic acid, the optimal xylose concentration for BC production was 20 g l(-1). In the medium containing 20 g l(-1) xylose, the xylose utilization and BC production by G. xylinus were stimulated by acetic acid within certain concentration. The highest BC yield (1.35 ± 0.06 g l(-1)) was obtained in the medium containing 20 g l(-1) xylose and 3 g l(-1) acetic acid after 14 days. This value was 6.17-fold higher than the yield (0.21 ± 0.01 g l(-1)) in the medium only containing 20 g l(-1) xylose. The results analyzed by FE-SEM, FTIR, and XRD showed that acetic acid affected little on the microscopic morphology and physicochemical characteristics of BC. Base on the phenomenon observed, lignocellulosic acid hydrolysates (xylose and acetic acid are main carbon sources present in it) could be considered as one potential substrate for BC production.

  19. Absorption cross section for the 5νOH stretch of acetic acid and peracetic acid

    Science.gov (United States)

    Begashaw, I. G.; Collingwood, M.; Bililign, S.

    2009-12-01

    We report measurements of the absorption cross sections for the vibrational O-H stretch (5νOH) overtone transitions in glacial acetic acid and peracetic acid. The photochemistry that results from overtone excitation has been shown to lead to OH radical production in molecules containing O-H (HNO3, H2O2). In addition the overtone excitation has been observed to result in light initiated chemical reaction. A Cavity ring-down spectroscopy (CRDS) instrument comprising of an Nd:YAG pumped dye laser and 620nm high reflectivity mirrors (R=99.995%) was used to measure the cross sections. The dye laser wavelength was calibrated using water vapor spectrum and the HITRAN 2008 database. The instrument’s minimum detectable absorption is αmin =4.5 *10-9cm-1 Hz-1/2 at 2σ noise level near the peak of the absorption feature. This measurement is the first for acetic acid at this excitation level. Preliminary results for acetic acid show the peak occurs near 615nm. Procedures for separating the monomer and dimer contribution will be presented. We would like to acknowledge support from NSF award #0803016 and NOAA-EPP award #NA06OAR4810187.

  20. Catalytic oxidative conversion of cellulosic biomass to formic acid and acetic acid with exceptionally high yields

    KAUST Repository

    Zhang, Jizhe

    2014-09-01

    Direct conversion of raw biomass materials to fine chemicals is of great significance from both economic and ecological perspectives. In this paper, we report that a Keggin-type vanadium-substituted phosphomolybdic acid catalyst, namely H4PVMo11O40, is capable of converting various biomass-derived substrates to formic acid and acetic acid with high selectivity in a water medium and oxygen atmosphere. Under optimized reaction conditions, H4PVMo11O40 gave an exceptionally high yield of formic acid (67.8%) from cellulose, far exceeding the values achieved in previous catalytic systems. Our study demonstrates that heteropoly acids are generally effective catalysts for biomass conversion due to their strong acidities, whereas the composition of metal addenda atoms in the catalysts has crucial influence on the reaction pathway and the product selectivity. © 2013 Elsevier B.V.

  1. Oxidation of acetate through reactions of the citric acid cycle by Geobacter sulfurreducens in pure culture and in syntrophic coculture

    OpenAIRE

    2000-01-01

    Geobacter sulfurreducens strain PCA oxidized acetate to CO2 via citric acid cycle reactions during growth with acetate plus fumarate in pure culture, and with acetate plus nitrate in coculture with Wolinella succinogenes. Acetate was activated by succinyl-CoA:acetate CoA-transferase and also via acetate kinase plus phosphotransacetylase. Citrate was formed by citrate synthase. Soluble isocitrate and malate dehydrogenases reduced NADP+ and NAD+, respectively. Oxidation of 2-oxoglutarate was me...

  2. Tolerance to acetic acid is improved by mutations of the TATA-binding protein gene.

    Science.gov (United States)

    An, Jieun; Kwon, Hyeji; Kim, Eunjung; Lee, Young Mi; Ko, Hyeok Jin; Park, Hongjae; Choi, In-Geol; Kim, Sooah; Kim, Kyoung Heon; Kim, Wankee; Choi, Wonja

    2015-03-01

    Screening a library of overexpressing mutant alleles of the TATA-binding gene SPT15 yielded two Saccharomyces cerevisiae strains (MRRC 3252 and 3253) with enhanced tolerance to acetic acid. They were also tolerant to propionic acid and hydrogen peroxide. Transcriptome profile analysis identified 58 upregulated genes and 106 downregulated genes in MRRC 3252. Stress- and protein synthesis-related transcription factors were predominantly enriched in the upregulated and downregulated genes respectively. Eight deletion mutants for some of the highly downregulated genes were acetic acid-tolerant. The level of intracellular reactive oxygen species was considerably lessened in MRRC 3252 and 3253 upon exposure to acetic acid. Metabolome profile analysis revealed that intracellular concentrations of 5 and 102 metabolites were increased and decreased, respectively, in MRRC 3252, featuring a large increase of urea and a significant decrease of amino acids. The dur1/2Δmutant, in which the urea degradation gene DUR1/2 is deleted, displayed enhanced tolerance to acetic acid. Enhanced tolerance to acetic acid was also observed on the medium containing a low concentration of amino acids. Taken together, this study identified two SPT15 alleles, nine gene deletions and low concentration of amino acids in the medium that confer enhanced tolerance to acetic acid.

  3. Point mutation of H3/H4 histones affects acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

    2014-10-10

    The molecular mechanism of acetic acid tolerance in yeast remains unclear despite of its importance for efficient cellulosic ethanol production. In this study, we examined the effects of histone H3/H4 point mutations on yeast acetic acid tolerance by comprehensively screening a histone H3/H4 mutant library. A total of 24 histone H3/H4 mutants (six acetic acid resistant and 18 sensitive) were identified. Compared to the wild-type strain, the histone acetic acid-resistant mutants exhibited improved ethanol fermentation performance under acetic acid stress. Genome-wide transcriptome analysis revealed that changes in the gene expression in the acetic acid-resistant mutants H3 K37A and H4 K16Q were mainly related to energy production, antioxidative stress. Our results provide novel insights into yeast acetic acid tolerance on the basis of histone, and suggest a novel approach to improve ethanol production by altering the histone H3/H4 sequences.

  4. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System.

    Science.gov (United States)

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth and higher productivity over an extended period; the productivity exceeded that from non-pH-controlled fermentation. During electrodialysis fermentation in our system, 97.6 g of acetic acid was produced from 86.0 g of ethanol; the amount of acetic acid was about 2.4 times greater than that produced by non-pH-controlled fermentation (40.1 g of acetic acid produced from 33.8 g of ethanol). Maximum productivity of electrodialysis fermentation in our system was 2.13 g/h, a rate which was 1.35 times higher than that of non-pH-controlled fermentation (1.58 g/h).

  5. Comparison of acetic acid and ethanol sclerotherapy for simple renal cysts: clinical experience with 86 patients.

    Science.gov (United States)

    Cho, Young Jun; Shin, Ji Hoon

    2016-01-01

    To compare the efficacy and treatment session numbers of acetic acid to that of ethanol sclerotherapy for the treatment of simple renal cysts. Between February 2004 and June 2013, 86 patients with simple renal cysts underwent percutaneous aspiration and injection of 50 %-acetic-acid (42 cysts) and 95 %-ethanol (44 cysts). The patient demographics, volume reduction rate, number of treatment sessions, and complications were then analyzed. The volume reduction rate was 94.1 ± 7.6 % in the 50 %-acetic acid group and 94.7 ± 11.7 % in the 95 %-ethanol group, and without a statistical difference. The rates of complete remission, partial remission, and no response were 57.1, 42.9 and 0 %, respectively, for the acetic acid group, and 70.5, 25.0, and 4.5 %, respectively, for the ethanol group. No statistical difference was observed between the two groups. Compared to the acetic acid group, the ethanol group had a higher number of treatment sessions, i.e. 1.10 ± 0.30 in the acetic acid group and 1.80 ± 0.79 in the ethanol group. Mild flank pain was a minor complication that occurred in both groups. Acetic acid seems to have equivalent sclerosing effects on simple renal cysts compared with those of ethanol despites of fewer treatment sessions.

  6. Theoretical Study of Acetic Acid Association Based on Hydrogen Bonding Mechanism.

    Science.gov (United States)

    Zhang, Minhua; Chen, Lihang; Yang, Huaming; Ma, Jing

    2017-06-15

    Combining molecular dynamics (MD) and quantum chemistry (QM) simulation, the association mechanisms of acetic acid (AA) systems were examined. DFT methods were proposed to compare the hydrogen-bonding energies of variable acetic acid dimers and definitely provided the stable dimers configuration. Geometry parameters of dimers were also obtained by QM calculations, which were taken as the characteristic criteria for further MD analysis. Proportion of different acetic acid dimers in gas phase was obtained by Radial distribution function (RDF) analysis, and cyclic dimer with two O1-Ho hydrogen bonds was demonstrated as the most stable structure. While in the more complex liquid phase, the linear chain form was proved to be the most stable one. Furthermore, in the acetic acid-crotonaldehyde solution, the association configuration of acetic acid changed from the linear chain form to the cyclic dimer structure as the acetic acid concentration decreased gradually. This result would be significant for the chemical separation process of acetic acid-crotonaldehyde solutions.

  7. Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

    Science.gov (United States)

    Gullo, Maria; Giudici, Paolo

    2008-06-30

    This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters.

  8. KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS

    OpenAIRE

    Haibo Mao; Joseph M. Genco; Adriaan van Heiningen; Hemant Pendse

    2010-01-01

    The “near neutral hemicellulose extraction process” involves extraction of hemicellulose using green liquor prior to kraft pulping. Ancillary unit operations include hydrolysis of the extracted carbohydrates using sulfuric acid, removal of extracted lignin, liquid-liquid extraction of acetic acid, liming followed by separation of gypsum, fermentation of C5 and C6 sugars, and upgrading the acetic acid and ethanol products by distillation. The process described here is a variant of the “near n...

  9. Effects of Oxygen Availability on Acetic Acid Tolerance and Intracellular pH in Dekkera bruxellensis

    OpenAIRE

    Capusoni, C.; Arioli, S.; Zambelli, P.; Moktaduzzaman, M.; Mora, D. de; Compagno, C.

    2016-01-01

    The yeast Dekkera bruxellensis, associated with wine and beer production, has recently received attention, because its high ethanol and acid tolerance enables it to compete with Saccharomyces cerevisiae in distilleries that produce fuel ethanol. We investigated how different cultivation conditions affect the acetic acid tolerance of D. bruxellensis. We analyzed the ability of two strains (CBS 98 and CBS 4482) exhibiting different degrees of tolerance to grow in the presence of acetic acid und...

  10. Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: a kinetic approach.

    Science.gov (United States)

    Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K; Mukherjee, Kakali; Saha, Bidyut

    2013-05-15

    The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation.

  11. Kinetics of acetic acid synthesis from ethanol over a Cu/SiO2 catalyst

    DEFF Research Database (Denmark)

    Voss, Bodil; Schjødt, Niels Christian; Grunwaldt, Jan-Dierk;

    2011-01-01

    The dehydrogenation of ethanol via acetaldehyde for the synthesis of acetic acid over a Cu based catalyst in a new process is reported. Specifically, we have studied a Cu on SiO2 catalyst which has shown very high selectivity to acetic acid via acetaldehyde compared to competing condensation routes....... The dehydrogenation experiments were carried out in a flow through lab scale tubular reactor. Based on 71 data sets a power law kinetic expression has been derived for the description of the dehydrogenation of acetaldehyde to acetic acid. The apparent reaction order was 0.89 with respect to water and 0...

  12. Improvement on stability of square planar rhodium (Ⅰ) complexes for carbonylation of methanol to acetic acid

    Institute of Scientific and Technical Information of China (English)

    蒋华; 潘平来; 袁国卿; 陈新滋

    1999-01-01

    A series of square planar cis-dicarbonyl polymer coordinated rhodium complexes with uncoordinated donors near the central rhodium atoms for carbonylation of methanol to acetic acid are reported. Data of IR, XPS and thermal analysis show that these complexes are very stable. The intramolecular substitution reaction is proposed for their high stability. These complexes show excellent catalytic activity, selectivity and less erosion to the equipment for the methanol carbonylation to acetic acid. The distillation process may be used instead of flash vaporization in the manufacture of acetic acid, which reduces the investment on the equipment.

  13. Theophylline-7-acetic acid derivatives with amino acids as anti-tuberculosis agents.

    Science.gov (United States)

    Voynikov, Yulian; Valcheva, Violeta; Momekov, Georgi; Peikov, Plamen; Stavrakov, Georgi

    2014-07-15

    A series of amides were synthesized by condensation of theophylline-7-acetic acid and eight commercially available amino acid methyl ester hydrochlorides. Consecutive hydrolysis of six of the amido-esters resulted in the formation of corresponding amido-acids. The newly synthesized compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. The activity varied depending on the amino acid fragments and in seven cases exerted excellent values with MICs 0.46-0.26 μM. Assessment of the cytotoxicity revealed that the compounds were not cytotoxic against the human embryonal kidney cell line HEK-293T. The theophylline-7-acetamides containing amino acid moieties appear to be promising lead compounds for the development of antimycobacterial agents.

  14. Kinetics of Oxidation of Some Amino Acids by N-Chlorosaccharin in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2004-01-01

    Full Text Available The kinetics of oxidation of some amino acids namely, glycine, alanine, aspartic acid, arginine, and histidine, (AA by N-chlorosaccharin (NCSA in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism.

  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...

  16. Improved Acetic Acid Resistance in Saccharomyces cerevisiae by Overexpression of the WHI2 Gene Identified through Inverse Metabolic Engineering.

    Science.gov (United States)

    Chen, Yingying; Stabryla, Lisa; Wei, Na

    2016-01-29

    Development of acetic acid-resistant Saccharomyces cerevisiae is important for economically viable production of biofuels from lignocellulosic biomass, but the goal remains a critical challenge due to limited information on effective genetic perturbation targets for improving acetic acid resistance in the yeast. This study employed a genomic-library-based inverse metabolic engineering approach to successfully identify a novel gene target, WHI2 (encoding a cytoplasmatic globular scaffold protein), which elicited improved acetic acid resistance in S. cerevisiae. Overexpression of WHI2 significantly improved glucose and/or xylose fermentation under acetic acid stress in engineered yeast. The WHI2-overexpressing strain had 5-times-higher specific ethanol productivity than the control in glucose fermentation with acetic acid. Analysis of the expression of WHI2 gene products (including protein and transcript) determined that acetic acid induced endogenous expression of Whi2 in S. cerevisiae. Meanwhile, the whi2Δ mutant strain had substantially higher susceptibility to acetic acid than the wild type, suggesting the important role of Whi2 in the acetic acid response in S. cerevisiae. Additionally, overexpression of WHI2 and of a cognate phosphatase gene, PSR1, had a synergistic effect in improving acetic acid resistance, suggesting that Whi2 might function in combination with Psr1 to elicit the acetic acid resistance mechanism. These results improve our understanding of the yeast response to acetic acid stress and provide a new strategy to breed acetic acid-resistant yeast strains for renewable biofuel production.

  17. Improved Acetic Acid Resistance in Saccharomyces cerevisiae by Overexpression of the WHI2 Gene Identified through Inverse Metabolic Engineering

    Science.gov (United States)

    Chen, Yingying; Stabryla, Lisa

    2016-01-01

    Development of acetic acid-resistant Saccharomyces cerevisiae is important for economically viable production of biofuels from lignocellulosic biomass, but the goal remains a critical challenge due to limited information on effective genetic perturbation targets for improving acetic acid resistance in the yeast. This study employed a genomic-library-based inverse metabolic engineering approach to successfully identify a novel gene target, WHI2 (encoding a cytoplasmatic globular scaffold protein), which elicited improved acetic acid resistance in S. cerevisiae. Overexpression of WHI2 significantly improved glucose and/or xylose fermentation under acetic acid stress in engineered yeast. The WHI2-overexpressing strain had 5-times-higher specific ethanol productivity than the control in glucose fermentation with acetic acid. Analysis of the expression of WHI2 gene products (including protein and transcript) determined that acetic acid induced endogenous expression of Whi2 in S. cerevisiae. Meanwhile, the whi2Δ mutant strain had substantially higher susceptibility to acetic acid than the wild type, suggesting the important role of Whi2 in the acetic acid response in S. cerevisiae. Additionally, overexpression of WHI2 and of a cognate phosphatase gene, PSR1, had a synergistic effect in improving acetic acid resistance, suggesting that Whi2 might function in combination with Psr1 to elicit the acetic acid resistance mechanism. These results improve our understanding of the yeast response to acetic acid stress and provide a new strategy to breed acetic acid-resistant yeast strains for renewable biofuel production. PMID:26826231

  18. Acetic acid production from marine algae. Progress report No. 2, September 30 to December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, J E; Wise, D L

    1978-03-10

    Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicates that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ have been observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate.

  19. 1-Methylpyrrolidine-2-acetic Acid is not a Precursor of Tropane Alkaloids.

    Science.gov (United States)

    Huang, M N; Abraham, T W; Kim, S H; Leete, E

    1996-02-01

    1-Methylpyrrolidine-2-acetic acid and related compounds were studied as precursors in the biosynthesis of the tropane alkaloids in Erythroxylum coca and Datura innoxia. (R,S)-[1',2-(13)C2,2-(14)C,(15)N]-1-methylpyrrolidine-2- acid, (R,S)-[1',2'-(13)C2,1'-(14)C]-1-methylpyrrolidine-2-acetic acid, (R,S) [1',2'-(13)C2,1-(14)C]-1-methylpyrrolidine-2-acetate, and (R,S)-+2'-(14)C] methylpyrrolidine-2-acetic acid N-acetylcysteamine thioester were synthesized an intact plants by leaf-planting or hydroponic-feeding. Specific incorporation of compounds into ( - )-hyoscyamine, ( - )-scopolamine, ( - )-cocaine and the biosynthetically related cuscohygrine were very low. These results indicate that 1-methylpyrrolidine acid is not an efficient precursor of tropane alkaloids.

  20. Electrochemical evaluation of the inhibitory effects of acetic acid on Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    Yuan Zhenhong; Zhao Jinsheng; Yan Yongjie; Yang Zhengyu

    2006-01-01

    A mediated electrochemical method was proposed for toxic evaluation of acetic acid on S. cerevisiae AS.380, and menadione/ferricyanide was chosen as the mediator system. The variance in electrochemical response in the absence and presence of increasing concentrations of acetic acid were used to indicate the inhibitory effects of weak acid on the yeast. The inhibitory effects of acetic acid on glucose consumption during menadione mediated reduction of ferricyanide were also measured for comparison purpose. The relative limiting current and the glucose consumption were reduced by 64.5 % and 61%, respectively, in the presence of 4g/L acetic acid at pH 4.0. The results showed that the electrochemical method can provide us with an appropriate and convenient tool for cytotoxic evaluation.

  1. Acetic Acid Acts as a Volatile Signal To Stimulate Bacterial Biofilm Formation

    Science.gov (United States)

    Chen, Yun; Gozzi, Kevin; Yan, Fang

    2015-01-01

    ABSTRACT Volatiles are small air-transmittable chemicals with diverse biological activities. In this study, we showed that volatiles produced by the bacterium Bacillus subtilis had a profound effect on biofilm formation of neighboring B. subtilis cells that grew in proximity but were physically separated. We further demonstrated that one such volatile, acetic acid, is particularly potent in stimulating biofilm formation. Multiple lines of genetic evidence based on B. subtilis mutants that are defective in either acetic acid production or transportation suggest that B. subtilis uses acetic acid as a metabolic signal to coordinate the timing of biofilm formation. Lastly, we investigated how B. subtilis cells sense and respond to acetic acid in regulating biofilm formation. We showed the possible involvement of three sets of genes (ywbHG, ysbAB, and yxaKC), all encoding putative holin-antiholin-like proteins, in cells responding to acetic acid and stimulating biofilm formation. All three sets of genes were induced by acetate. A mutant with a triple mutation of those genes showed a severe delay in biofilm formation, whereas a strain overexpressing ywbHG showed early and robust biofilm formation. Results of our studies suggest that B. subtilis and possibly other bacteria use acetic acid as a metabolic signal to regulate biofilm formation as well as a quorum-sensing-like airborne signal to coordinate the timing of biofilm formation by physically separated cells in the community. PMID:26060272

  2. Mechanistic Insights Underlying Tolerance to Acetic Acid Stress in Vaginal Candida glabrata Clinical Isolates.

    Science.gov (United States)

    Cunha, Diana V; Salazar, Sara B; Lopes, Maria M; Mira, Nuno P

    2017-01-01

    During colonization of the vaginal tract Candida glabrata cells are challenged with the presence of acetic acid at a low pH, specially when dysbiosis occurs. To avoid exclusion from this niche C. glabrata cells are expected to evolve efficient adaptive responses to cope with this stress; however, these responses remain largely uncharacterized, especially in vaginal strains. In this work a cohort of 18 vaginal strains and 2 laboratory strains (CBS138 and KUE100) were phenotyped for their tolerance against inhibitory concentrations of acetic acid at pH 4. Despite some heterogeneity has been observed among the vaginal strains tested, in general these strains were considerably more tolerant to acetic acid than the laboratory strains. To tackle the mechanistic insights behind this differential level of tolerance observed, a set of vaginal strains differently tolerant to acetic acid (VG281∼VG49 acetic acid the more tolerant vaginal strains exhibited a higher activity of the plasma membrane proton pump CgPma1 and a reduced internal accumulation of the acid, these being two essential features to maximize tolerance. Based on the higher level of resistance exhibited by the vaginal strains against the action of a β-1,3-glucanase, it is hypothesized that the reduced internal accumulation of acetic acid inside these strains may originate from them having a different cell wall structure resulting in a reduced porosity to undissociated acetic acid molecules. Both the vaginal and the two laboratory strains were found to consume acetic acid in the presence of glucose indicating that metabolization of the acid is used by C. glabrata species as a detoxification mechanism. The results gathered in this study advance the current knowledge on the mechanisms underlying the increased competitiveness of C. glabrata in the vaginal tract, a knowledge that can be used to guide more suitable strategies to treat infections caused by this pathogenic yeast.

  3. Establishing the ellipsoidal geometry of a benzoic acid-based amphiphile via dimer switching: insights from intramolecular rotation and facial H-bond torsion.

    Science.gov (United States)

    Ramesh, Nivarthi; Sarangi, Nirod Kumar; Patnaik, Archita

    2013-05-01

    Soft molecular ellipsoids conceived from 3,4-di(dodecyloxy)benzoic acid (DDBA) amphiphile draw attention to monomer structure design, intramolecular -COOH headgroup twist (ϕ°) and cyclic-acyclic dimer switching through facial H-bond torsion (ψ°). Generically, precipitation in hydrogen bonded systems has been the prime phenomenon once the critical aggregation concentrations were reached in the bulk solution. DDBA was no exception to this generalization. It formed precipitates in chloroform and methanol with no specific geometry but with cyclic dimer motifs in them. On the contrary, surface pressure modulated interfacial aggregation with ellipsoidal geometry followed acyclic dimerization (catemer motif) with various levels of headgroup torsion, established through real-time polarization modulated infrared reflection-absorption spectroscopy (IRRAS) and density functional theory (DFT) calculations, that estimated the energy costs for these unexplored pathways. The reaction coordinates ϕ° and ψ° in consonance with 2D surface pressure modulation thus directed the shape anisotropy during the dynamic self-assembly of DDBA. Changes in subphase pH and metal ionic environment had a derogatory effect on the ellipsoid formation, the structural requirement for which strictly followed a stringent need for twin alkyl chains in an asymmetric unit cell, as 4-dodecyloxybenzoic acid (MABA) with a single alkyl chain formed exclusively spherical assemblies with no dimer modulation. The investigation thus reports unexplored energy pathways toward ellipsoidal geometry of the amphiphile in the course of its interfacial aggregation.

  4. EFFECT OF SUBSTITUTION POSITION OF HYDROXY GROUP AT BENZOIC ACID ON THE LUMINESCENT AND DEGRADATION PROPERTIES OF POLY[DI(CARBOXYPHENYL) SUCCINATE-co-SEBACIC ANHYDRIDE]S

    Institute of Scientific and Technical Information of China (English)

    Jun Fan; Hong-liang Jiang; Kang-jie Zhu

    2007-01-01

    In this work, two new diacids, di(m-carboxyphenyl) succinate (m-dCPS) and di(o-carboxyphenyl) succinate (o-dCPS), were synthesized by reaction of m-, o-hydroxy benzoic acid with succinic chloride, respectively. Their corresponding copolymers with sebacic acid (SA), P(m-dCPS:SA) and P(o-dCPS:SA), were prepared by melt copolycondensation and characterized by NMR, UV and DSC methods. Compared with inherently fluorescent poly[di(p-carboxyphenyl) succinateco-sebacic anhydride] (P(p-dCPS:SA)), P(m-dCPS:SA) and P(o-dCPS:SA) displayed different luminescent properties. P(m-dCPS:SA) could emit fluorescence under the excitation of both visible and UV light, while P(o-dCPS:SA) could only emit fluorescence when excited with UV light. Degradation rate of the two new copolyanhydrides increased with the increase of SA fraction in the copolymers. In addition, P(o-dCPS:SA) degraded more rapidly than P(m-dCPS:SA) with the same composition. Typical surface-degradation characteristics of these copolyanhydrides were observed.

  5. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Science.gov (United States)

    Xiong, Pingping; Li, Jie; Bu, Huaiyu; Wei, Qing; Zhang, Ruolin; Chen, Sanping

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu0.5L]n (1), [Cu(HL)2Cl2]n (2), [Cu(HL)2Cl2(H2O)] (3), [Cu(L)2(H2O)]n (4) and [Cu(L)(phen)(HCO2)]n (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl-, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units -Cu-O-Cu-O- are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated.

  6. Kinetics of Oxidation of 3-Benzoylpropionic Acid by N-Chlorobenzamide in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2011-01-01

    Full Text Available The kinetics of oxidation of 3-benzoylpropionic acid (KA by N-chlorobenzamide (NCB in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order dependence each in [KA], [NCB] and [H+]. The main product of the oxidation is the corresponding carboxylic acid. The rate decreases with the addition of benzamide, one of the products of the reaction. Variation in ionic strength of the reaction medium has no significant effect on the rate of oxidation. But the rate of the reaction is enhanced by lowering the dielectric constant of the reaction medium. Hypochlorous acidium ion (H2O+Cl, has been postulated as the reactive oxidizing species. A mechanism consistent with observed results have been proposed and the related rate law deduced. The activation parameters have been computed with respect to slow step of the mechanism.

  7. 原料乳中苯甲酸质量分数控制措施的研究进展%Research advance in the control measures of the content of benzoic acid in raw milk

    Institute of Scientific and Technical Information of China (English)

    李晰晖; 任国谱

    2013-01-01

    对苯甲酸对人体的危害、在原料乳中的主要来源以及原料乳的卫生质量、马尿酸的质量分数和人为添加等因素对原料乳中苯甲酸质量分数的影响进行了综述,对提高原料乳的卫生质量、安全无毒的防腐措施和快速高效的检测手段等控制原料乳中苯甲酸质量分数的方法进行了讨论..%The research advance in the harm of benzoic acid to the body ,the source of it in raw milk and in factors influencing the content of benzoic acid such as hygienic quality of raw milk.the content of hippuric acid,anthropic addition were summarized in the paper.In addition,this paper discussed the methods how to cntrol the content of benzoic acid in raw milk including improving the hygienic quality of raw milk,se-cure and nontoxic antiseptic measures, fast and effective detecting methods.

  8. Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets

    DEFF Research Database (Denmark)

    Canibe, Nuria; Pedersen, Anni Øyan; Jensen, Bent Borg

    2010-01-01

    of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has been suggested to be determinant in reducing feed intake by impairing palatability. However, this hypothesis has never been investigated. A study was carried out to determine the impact of increasing levels of acetic...... acid in FLF on feed intake of weaners. Three experimental FLF diets were prepared to contain varying levels of acetic acid (30, 60, and 120 mM). Twenty piglets per treatment, weaned at 4 weeks of age and housed individually, were fed the experimental diets during six weeks starting at weaning. Feed...... intake and body weight were registered weekly. The results showed that high acetic acid concentration in FLF, accompanied by a slight lower pH level, tended to decrease feed intake without affecting body weight gain. This discrepancy could partly be explained by the difficulty in measuring accurately...

  9. Hydrogen peroxide resistance of Acetobacter pasteurianus NBRC3283 and its relationship to acetic acid fermentation.

    Science.gov (United States)

    Okamoto-Kainuma, Akiko; Ehata, Yasunori; Ikeda, Manami; Osono, Takemasa; Ishikawa, Morio; Kaga, Takayuki; Koizumi, Yukimichi

    2008-10-01

    The bacterium Acetobacter pasteurianus can ferment acetic acid, a process that proceeds at the risk of oxidative stress. To understand the stress response, we investigated catalase and OxyR in A. pasteurianus NBRC3283. This strain expresses only a KatE homolog as catalase, which is monofunctional and growth dependent. Disruption of the oxyR gene increased KatE activity, but both the katE and oxyR mutant strains showed greater sensitivity to hydrogen peroxide as compared to the parental strain. These mutant strains showed growth similar to the parental strain in the ethanol oxidizing phase, but their growth was delayed when cultured in the presence of acetic acid and of glycerol and during the acetic acid peroxidation phase. The results suggest that A. pasteurianus cells show different oxidative stress responses between the metabolism via the membrane oxidizing pathway and that via the general aerobic pathway during acetic acid fermentation.

  10. Comparison of Cultivable Acetic Acid Bacterial Microbiota in Organic and Conventional Apple Cider Vinegar

    National Research Council Canada - National Science Library

    Aleksandra Stornik; Barbara Skok; Janja Trcek

    2016-01-01

      The authors compared the cultivable acetic acid bacterial microbiota in the production of organic and conventional apple cider vinegars from a smoothly running oxidation cycle of a submerged industrial process...

  11. Pretreatment and fermentation strategies to overcome the toxicity of acetic acid in hemicellulosic hydrolysates

    DEFF Research Database (Denmark)

    Mussatto, Solange I.

    Acetic acid is one of the most important toxic compounds present in hemicellulosic hydrolysates. In order to overcome this problem, several strategies were studied for both biomass pretreatment and fermentation steps. Biomass deacetylation by mild alkaline pretreatment or using high pressure CO2...... were considered interesting strategies to selectively remove acetic acid from biomass structure. In addition, the selective removal of acetic acid from biomass as a first step in the whole biomass conversion chain, contribute for the development and implementation of competitive biorefinery platforms...... where acetic acid can also be integrated as a valuable final product. For the fermentation step, it is well known that hemicellulosic hydrolysates usually need to be detoxified prior use as fermentation medium in order to improve the performance of the microorganism to convert sugars in the product...

  12. Synthesis of 2-(Benzodioxol-2-yl)acetic Acids as PPARδ Agonists

    Institute of Scientific and Technical Information of China (English)

    Jian Lei KANG; Zhi Bing ZHENG; Dan QIN; Li Li WANG; Song LI

    2006-01-01

    A new series of compounds, 2-(benzodioxol-2-yl)acetic acids, have been synthesized. Their structures were confirmed by MS and 1H-NMR. The preliminary pharmacological screening showed that these compounds exhibited potent human PPARδ agonist activities.

  13. Oxidative aromatization of Hantzsch 1,4-dihydropyridines by aqueous hydrogen peroxide-acetic acid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simple method for the oxidative aromatization of Hantzsch 1,4-dihydropyridines to the corresponding pyridines is achieved by using hydrogen peroxide as green oxidant and acetic acid as catalyst in aqueous solution.

  14. Growing and laying performance of Japanese quail fed diet supplemented with different concentrations of acetic acid

    Directory of Open Access Journals (Sweden)

    Youssef A. Attia

    2013-04-01

    Full Text Available In order to evaluate the effect of acetic acid on growing and laying performance of Japanese Quail (JQ, 180 15-day-old JQ were divided into 4 groups. During the growing (15-42 days of age and laying (43-84 days of age periods, the groups fed the same basal diets supplemented with 0, 1.5, 3 and 6% of acetic acid. Each diet was fed to five replicates of 9 JQ (3 males:6 females during the growing period. During the laying period, 128 birds were housed in 32 cages (4 birds per cage, 1 male and 3 females, 8 replicates per treatment. Birds were housed in wire cages (46L×43W×20H cm in an open room. Acetic acid supplementation at 3% in the diets significantly increased the growth and laying rate and the Haugh unit score. The liver percentage significantly decreased with acetic acid at 6%. Acetic acid at 3% significantly increased hemoglobin concentrations at 6 weeks of age and increased weight of day old chicks hatched. Acetic acid affected the immune system as manifested by an excess of cellular reactions in the intestine as well as lymphoid hyperplasia in the spleen tissue. Degenerative changes in the covering epithelium of the intestinal villi were noted at the 6% concentration of acetic acid. Hepatocyte vacuolation and fatty changes were also observed at this concentration of treatment. In conclusion, 3% acetic acid may be used as a feed supplement for JQ during the growing and laying period to improve the productive performance.

  15. Comparison of Cultivable Acetic Acid Bacterial Microbiota in Organic and Conventional Apple Cider Vinegar

    OpenAIRE

    2016-01-01

    Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. We compared the cultivable ...

  16. The Fate of Acetic Acid during Glucose Co-Metabolism by the Spoilage Yeast Zygosaccharomyces bailii

    OpenAIRE

    Fernando Rodrigues; Maria João Sousa; Paula Ludovico; Helena Santos; Manuela Côrte-Real; Cecília Leão

    2012-01-01

    Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate me...

  17. KINETIC OF ESTERIFICATION OF ETHYL ALCOHOL BY ACETIC ACID ON A CATALYTIC RESIN

    Directory of Open Access Journals (Sweden)

    Erol İNCE

    2002-01-01

    Full Text Available The conversion kinetics of diluted acetic acid to ethyl acetate by ethanol esterification in a batch reactor in liquid phase with an acidic polymer catalyst (lewatit series was studied. The intrinsic rate constants have been correlated with the reaction temperature, concentration of catalyst, initial ratios of reactants and initial water concentrations. The kinetic analysis was restricted to the system at hand in which a liquid and vapor phase are at equilibrium.

  18. SINOPEC,BP TO LAUNCH ACETIC ACID JOINT VENTURE IN NANJING

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Sinopec Corp and BP signed a 50%-50% joint venture contract on March 15 to build a world-class 500,000-ton acetic acid plant in Nanjing, the capital of East China's Jiangsu Province. The joint venture, which is expected to be on stream in the second half of 2007,will adopt BP's world leading CativaR technology to make this project become a acetic acid production base with great competitiveness.

  19. Engineering Escherichia coli to convert acetic acid to β-caryophyllene.

    Science.gov (United States)

    Yang, Jianming; Nie, Qingjuan

    2016-05-05

    Under aerobic conditions, acetic acid is the major byproduct produced by E. coli during the fermentation. And acetic acid is detrimental to cell growth as it destroys transmembrane pH gradients. Hence, how to reduce the production of acetic acid and how to utilize it as a feedstock are of intriguing interest. In this study, we provided an evidence to produce β-caryophyllene by the engineered E. coli using acetic acid as the only carbon source. Firstly, to construct the robust acetate-utilizing strain, acetyl-CoA synthases from three different sources were introduced and screened in the E. coli. Secondly, to establish the engineered strains converting acetic acid to β-caryophyllene, acetyl-CoA synthase (ACS), β-caryophyllene synthase (QHS1) and geranyl diphosphate synthase (GPPS2) were co-expressed in the E. coli cells. Thirdly, to further enhance β-caryophyllene production from acetic acid, the heterologous MVA pathway was introduced into the cells. What's more, acetoacetyl-CoA synthase (AACS) was also expressed in the cells to increase the precursor acetoacetyl-CoA and accordingly resulted in the increase of β-caryophyllene. The final genetically modified strain, YJM67, could accumulate the production of biomass and β-caryophyllene up to 12.6 and 1.05 g/L during 72 h, respectively, with a specific productivity of 1.15 mg h(-1) g(-1) dry cells, and the conversion efficiency of acetic acid to β-caryophyllene (gram to gram) reached 2.1%. The yield of β-caryophyllene on acetic acid of this strain also reached approximately 5.6% of the theoretical yield. In the present study, a novel biosynthetic pathway for β-caryophyllene has been investigated by means of conversion of acetic acid to β-caryophyllene using an engineered Escherichia coli. This was the first successful attempt in β-caryophyllene production by E. coli using acetic acid as the only carbon source. Therefore, we have provided a new metabolic engineering tool for β-caryophyllene synthesis.

  20. Drug resistance marker-aided genome shuffling to improve acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Zheng, Dao-Qiong; Wu, Xue-Chang; Wang, Pin-Mei; Chi, Xiao-Qin; Tao, Xiang-Lin; Li, Ping; Jiang, Xin-Hang; Zhao, Yu-Hua

    2011-03-01

    Acetic acid existing in a culture medium is one of the most limiting constraints in yeast growth and viability during ethanol fermentation. To improve acetic acid tolerance in Saccharomyces cerevisiae strains, a drug resistance marker-aided genome shuffling approach with higher screen efficiency of shuffled mutants was developed in this work. Through two rounds of genome shuffling of ultraviolet mutants derived from the original strain 308, we obtained a shuffled strain YZ2, which shows significantly faster growth and higher cell viability under acetic acid stress. Ethanol production of YZ2 (within 60 h) was 21.6% higher than that of 308 when 0.5% (v/v) acetic acid was added to fermentation medium. Membrane integrity, higher in vivo activity of the H+-ATPase, and lower oxidative damage after acetic acid treatment are the possible reasons for the acetic acid-tolerance phenotype of YZ2. These results indicated that this novel genome shuffling approach is powerful to rapidly improve the complex traits of industrial yeast strains.

  1. Insights into the mechanism of acetic acid hydrogenation to ethanol on Cu(111) surface

    Science.gov (United States)

    Zhang, Minhua; Yao, Rui; Jiang, Haoxi; Li, Guiming; Chen, Yifei

    2017-08-01

    Density functional theory (DFT) calculations were employed to theoretically explain the reaction mechanism of acetic acid hydrogenation to ethanol on Cu catalyst. The activation barriers of key elementary steps and the adsorption configurations of key intermediates involved in acetic acid hydrogenation on Cu(111) surface were investigated. The results indicated that the direct dissociation of acetic acid to acetyl (CH3COOH → CH3CO + OH) is the rate-determined step. The activation barrier of acetic acid scission to acetyl and the adsorption energy of acetic acid are two descriptors which could determine the conversion of acetic acid. The descriptors might have effects on the ethanol selectivity including: the adsorption energy of acetaldehyde and the activation barriers for Osbnd H bond formation of C2-oxygenates (CH3CO + H → CH3COH, CH3CHO + H → CH3CHOH and CH3CH2O + H → CH3CH2OH). These proposed descriptors could be used as references to design new Cu-based catalysts that have excellent catalytic performance.

  2. Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations

    Directory of Open Access Journals (Sweden)

    Päivi Ylitervo

    2014-07-01

    Full Text Available The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L−1 acetic acid at pH 5.0, at a dilution rate of 0.5 h−1. The cultivations were performed at both high (~25 g·L−1 and very high (100–200 g·L−1 yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L−1 sucrose, at volumetric rates of 5–6 g·L−1·h−1 at acetic acid concentrations up to 15.0 g·L−1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L−1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials.

  3. Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats

    Science.gov (United States)

    Breza, Joseph M.

    2012-01-01

    Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH4Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003–0.1 M acetic acid, and 0.003–0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds. PMID:22896718

  4. Effect of manganese ions on ethanol fermentation by xylose isomerase expressing Saccharomyces cerevisiae under acetic acid stress.

    Science.gov (United States)

    Ko, Ja Kyong; Um, Youngsoon; Lee, Sun-Mi

    2016-12-01

    The efficient fermentation of lignocellulosic hydrolysates in the presence of inhibitors is highly desirable for bioethanol production. Among the inhibitors, acetic acid released during the pretreatment of lignocellulose negatively affects the fermentation performance of biofuel producing organisms. In this study, we evaluated the inhibitory effects of acetic acid on glucose and xylose fermentation by a high performance engineered strain of xylose utilizing Saccharomyces cerevisiae, SXA-R2P-E, harboring a xylose isomerase based pathway. The presence of acetic acid severely decreased the xylose fermentation performance of this strain. However, the acetic acid stress was alleviated by metal ion supplementation resulting in a 52% increased ethanol production rate under 2g/L of acetic acid stress. This study shows the inhibitory effect of acetic acid on an engineered isomerase-based xylose utilizing strain and suggests a simple but effective method to improve the co-fermentation performance under acetic acid stress for efficient bioethanol production.

  5. Effects of acetic acid and lactic acid on physicochemical characteristics of native and cross-linked wheat starches.

    Science.gov (United States)

    Majzoobi, Mahsa; Beparva, Paniz

    2014-03-15

    The effects of two common organic acids; lactic and acetic acids (150 mg/kg) on physicochemical properties of native and cross-linked wheat starches were investigated prior and after gelatinization. These acids caused formation of some cracks and spots on the granules. The intrinsic viscosity of both starches decreased in the presence of the acids particularly after gelatinization. Water solubility increased while water absorption reduced after addition of the acids. The acids caused reduction in gelatinization temperature and enthalpy of gelatinization of both starches. The starch gels became softer, less cohesive, elastic and gummy when acids were added. These changes may indicate the degradation of the starch molecules by the acids. Cross-linked wheat starch was more resistant to the acids. However, both starches became more susceptible to the acids after gelatinization. The effect of lactic acid on physicochemical properties of both starches before and after gelatinization was greater than acetic acid.

  6. [Advances in the progress of anti-bacterial biofilms properties of acetic acid].

    Science.gov (United States)

    Gao, Xinxin; Jin, Zhenghua; Chen, Xinxin; Yu, Jia'ao

    2016-06-01

    Bacterial biofilms are considered to be the hindrance in the treatment of chronic wound, because of their tolerance toward antibiotics and other antimicrobial agents. They also have strong ability to escape from the host immune attack. Acetic acid, as a kind of organic weak acid, can disturb the biofilms by freely diffusing through the bacterial biofilms and bacterial cell membrane structure. Then the acid dissociates to release the hydrogen ions, leading to the disorder of the acid-base imbalance, change of protein conformation, and the degradation of the DNA within the membranes. This paper reviews the literature on the characteristics and treatment strategies of the bacterial biofilms and the acetic acid intervention on them, so as to demonstrate the roles acetic acid may play in the treatment of chronic wound, and thus provide a convincing treatment strategy for this kind of disease.

  7. Comparison of D-gluconic acid production in selected strains of acetic acid bacteria.

    Science.gov (United States)

    Sainz, F; Navarro, D; Mateo, E; Torija, M J; Mas, A

    2016-04-01

    The oxidative metabolism of acetic acid bacteria (AAB) can be exploited for the production of several compounds, including D-gluconic acid. The production of D-gluconic acid in fermented beverages could be useful for the development of new products without glucose. In the present study, we analyzed nineteen strains belonging to eight different species of AAB to select those that could produce D-gluconic acid from D-glucose without consuming D-fructose. We tested their performance in three different media and analyzed the changes in the levels of D-glucose, D-fructose, D-gluconic acid and the derived gluconates. D-Glucose and D-fructose consumption and D-gluconic acid production were heavily dependent on the strain and the media. The most suitable strains for our purpose were Gluconobacter japonicus CECT 8443 and Gluconobacter oxydans Po5. The strawberry isolate Acetobacter malorum (CECT 7749) also produced D-gluconic acid; however, it further oxidized D-gluconic acid to keto-D-gluconates.

  8. The fraction of cells that resume growth after acetic acid addition is a strain-dependent parameter of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Swinnen, Steve; Fernández-Niño, Miguel; González-Ramos, Daniel; van Maris, Antonius J A; Nevoigt, Elke

    2014-06-01

    High acetic acid tolerance of Saccharomyces cerevisiae is a relevant phenotype in industrial biotechnology when using lignocellulosic hydrolysates as feedstock. A screening of 38 S. cerevisiae strains for tolerance to acetic acid revealed considerable differences, particularly with regard to the duration of the latency phase. To understand how this phenotype is quantitatively manifested, four strains exhibiting significant differences were studied in more detail. Our data show that the duration of the latency phase is primarily determined by the fraction of cells within the population that resume growth. Only this fraction contributed to the exponential growth observed after the latency phase, while all other cells persisted in a viable but non-proliferating state. A remarkable variation in the size of the fraction was observed among the tested strains differing by several orders of magnitude. In fact, only 11 out of 10(7)  cells of the industrial bioethanol production strain Ethanol Red resumed growth after exposure to 157 mM acetic acid at pH 4.5, while this fraction was 3.6 × 10(6) (out of 10(7)  cells) in the highly acetic acid tolerant isolate ATCC 96581. These strain-specific differences are genetically determined and represent a valuable starting point to identify genetic targets for future strain improvement.

  9. Acetate accumulation enhances mixed culture fermentation of biomass to lactic acid.

    Science.gov (United States)

    Khor, Way Cern; Roume, Hugo; Coma, Marta; Vervaeren, Han; Rabaey, Korneel

    2016-10-01

    Lactic acid is a high-in-demand chemical, which can be produced through fermentation of lignocellulosic feedstock. However, fermentation of complex substrate produces a mixture of products at efficiencies too low to justify a production process. We hypothesized that the background acetic acid concentration plays a critical role in lactic acid yield; therefore, its retention via selective extraction of lactic acid or its addition would improve overall lactic acid production and eliminate net production of acetic acid. To test this hypothesis, we added 10 g/L of acetate to fermentation broth to investigate its effect on products composition and concentration and bacterial community evolution using several substrate-inoculum combinations. With rumen fluid inoculum, lactate concentrations increased by 80 ± 12 % (cornstarch, p 69 % lactic acid bacteria (LAB), predominantly Lactobacillaceae. Higher acetate concentration promoted a more diverse LAB population, especially on non-inoculated bottles. In subsequent tests, acetate was added in a semi-continuous percolation system with grass as substrate. These tests confirmed our findings producing lactate at concentrations 26 ± 5 % (p lactic acid production from waste biomass to levels more attractive for application.

  10. Effects of the use of acetic acid as the conservant in lucerne ensiling

    Directory of Open Access Journals (Sweden)

    Đorđević Nenad

    2004-01-01

    Full Text Available The influence of acetic acid as the chemical conservant in three doses (4, 6 8 g/kg green mass on the intensity of fermentation and proteolysis in lucerne silage was investigated. On the basis of chemical analysis, it was found that with the increase of conservant dose the pH value decreased aminogenesis and nitrogen solubility was limited. In silages treated the absolute and relative domination of acetic acid was found in total acid content. The increase of free and bonded acetic acid was discovered with the increase of conservant dose. Free butyric acid was not detected, while bonded butyric acid was present in negligible concentration, without effect on silage quality. Compared to control silage (III quality class according to DLG and Zelter method, a significant increase of acetic acid in silages resulted in the decline of their quality, and they were ranked as not useful (V quality class according to DLG method, or on the margin of usefulness (IV quality class according to Zelter method. In spite of some foreign references, domestic experiences show that acetic acid is not an effective conservant and it is not recommended for that use for lucerne that is not simple to ensile.

  11. Kinetics of Oxidation of 3-Benzoylpropionic Acid by N-Bromoacetamide in Aqueous Acetic Acid Medium

    Directory of Open Access Journals (Sweden)

    N. A. Mohamed Farook

    2011-01-01

    Full Text Available The kinetics of oxidation of 3-benzoylpropionic acid (KA with N-bromoacetamide (NBA have been studied potentiometrically in 50:50 (v/v aqueous acetic acid medium at 298 K The reaction was first order each with respect to [KA], [NBA] and [H+]. The main product of the oxidation is the corresponding carboxylic acid. The rate decreases with the addition of acetamide, one of the products of the reaction. Variation in ionic strength of the reaction medium has no significant effect on the rate of oxidation. But the rate of the reaction is enhanced by lowering the dielectric constant of the reaction medium. A mechanism consistent with observed results have been proposed and the related rate law was deduced.

  12. Comparison of open-flow microperfusion and microdialysis methodologies when sampling topically applied fentanyl and benzoic acid in human dermis ex vivo

    DEFF Research Database (Denmark)

    Holmgaard, R; Benfeldt, E; Nielsen, J B

    2012-01-01

    . The second purpose was to provide guidance to researchers in choosing the most efficient method for a given penetrant and give suggestions concerning critical choices for successful dermal sampling. METHODS: The dOFM and dMD techniques are compared in equal set-ups using three probe-types (one dOFM probe...... and two dMD probe-types) in donor skin (n = 9)--27 probes of each type sampling each penetrant in solutions applied in penetrationchambers glued to the skin surface over a time range of 20 h. RESULTS: Pharmacokinetic results demonstrated concordance between dOFM and dMD sampling technique under the given......PURPOSE: The purpose of this study is to compare two sampling methods--dermal Open-Flow Microperfusion (dOFM) and dermal Microdialysis (dMD) in an international joint experiment in a single-laboratory setting. We used human ex-vivo skin and sampled topically administered Fentanyl and Benzoic Acid...

  13. Molecular structure, vibrational, UV, NMR, HOMO-LUMO, MEP, NLO, NBO analysis of 3,5 di tert butyl 4 hydroxy benzoic acid

    Science.gov (United States)

    Mathammal, R.; Sangeetha, K.; Sangeetha, M.; Mekala, R.; Gadheeja, S.

    2016-09-01

    In this study, we report a combined experimental and theoretical study on molecular structure and vibrational spectra of 3,5 di tert butyl 4 hydroxy benzoic acid. The properties of title compound have been evaluated by quantum chemical calculation (DFT) using B3LYP functional and 6-31 + G (d, p) as basis set. IR Spectra has been recorded using Fourier transform infrared spectroscopy (FT-IR) in the region 4000-400 cm-1. The vibrational assignment of the calculated normal modes has been made on the basis set. The isotropic chemical shifts computed by 13C and 1H NMR (Nuclear Magnetic Resonance) analyses also show good agreement with experimental observations. The theoretical UV-Vis spectrum of the compound are used to study the visible absorption maxima (λ max). The structure activity relationship have been interpreted by mapping electrostatic potential surface (MEP), which is valuable information for the quality control of medicines and drug receptor interactions. The Mullikan charges, HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital) energy are analyzed. HOMO-LUMO energy gap and other related molecular properties are also calculated. The Natural Bond Orbital (NBO) analysis is carried out to investigate the various intra and inter molecular interactions of molecular system. The Non-linear optical properties such as dipole moment (μ), polarizability (αtot) and molecular first order hyperpolarizability (β) of the title compound are computed with B3LYP/6-31 + G (d,p) level of theory.

  14. Synthesis, Biological, and Quantum Chemical Studies of Zn(II and Ni(II Mixed-Ligand Complexes Derived from N,N-Disubstituted Dithiocarbamate and Benzoic Acid

    Directory of Open Access Journals (Sweden)

    Anthony C. Ekennia

    2016-01-01

    Full Text Available Some mixed-ligand complexes of Zn(II and Ni(II derived from the sodium salt of N-alkyl-N-phenyl dithiocarbamate and benzoic acid have been prepared. The complexes are represented as ZnMDBz, ZnEDBz, NiMDBz, and NiEDBz (MD: N-methyl-N-phenyl dithiocarbamate, ED: N-ethyl-N-phenyl dithiocarbamate, and Bz: benzoate; and their coordination behavior was characterized on the basis of elemental analyses, IR, electronic spectra, magnetic and conductivity measurements, and quantum chemical calculations. The magnetic moment measurement and electronic spectra were in agreement with the four proposed coordinate geometries for nickel and zinc complexes and were corroborated by the theoretical quantum chemical calculations. The quantum chemically derived thermodynamics parameters revealed that the formation of N-methyl-N-phenyl dithiocarbamate complexes is more thermodynamically favourable than that of the N-ethyl-N-phenyl dithiocarbamate complexes. The bioefficacy of the mixed-ligand complexes examined against different microbes showed moderate to high activity against the test microbes. The anti-inflammatory and antioxidant studies of the metal complexes showed that the ethyl substituted dithiocarbamate complexes exhibited better anti-inflammatory and antioxidant properties than the methyl substituted dithiocarbamate complexes.

  15. Synthesis and spectroscopic characterization on 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid: A DFT approach.

    Science.gov (United States)

    Kurt, M; Sas, E Babur; Can, M; Okur, S; Icli, S; Demic, S; Karabacak, M; Jayavarthanan, T; Sundaraganesan, N

    2016-01-05

    A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) (13)C NMR and (1)H NMR chemical shift values of (TPBA), in the ground state have been calculated by using ab initio density functional theory (DFT/B3LYP) method with 6-311G(d,p) as basis set for the first time. Comparison of the observed fundamental vibrational modes of (TPBA) and calculated results by DFT/B3LYP method indicates that B3LYP level of theory giving yield good results for quantum chemical studies. Vibrational wavenumbers obtained by the DFT/B3LYP method are in good agreement with the experimental data. The study was complemented with a natural bond orbital (NBO) analysis, to evaluate the significance of hyperconjugative interactions and electrostatic effects on such molecular structure. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals analysis and thermodynamic properties of TPBA were investigated using theoretical calculations.

  16. De novo sequencing and transcriptome analysis of Pinellia ternata identify the candidate genes involved in the biosynthesis of benzoic acid and ephedrine

    Directory of Open Access Journals (Sweden)

    Zhang Guang Hui

    2016-08-01

    Full Text Available Background: The medicinal herb, Pinellia ternate, is purported to be an anti-emetic with analgesic and sedative effects. Alkaloids are the main biologically active compounds in P. ternata, especially ephedrine that is a phenylpropylamino alkaloid specifically produced by Ephedra and Catha edulis. However, how ephedrine is synthesized in plants is uncertain. Only the phenylalanine ammonia lyase (PAL and relevant genes in this pathway have been characterized. Genomic information of P. ternata is also unavailable. Results: We analyzed the transcriptome of the tuber of P. ternata with the Illumina HiSeqTM 2000 sequencing platform. 66,813,052 high-quality reads were generated, and these reads were assembled de novo into 89,068 unigenes. Most known genes involved in benzoic acid biosynthesis were identified in the unigene dataset of P. ternate, and the expression patterns of some ephedrine biosynthesis-related genes were analyzed by reverse transcription quantitative real-time PCR (RT-qPCR. Also, 14,468 simple sequence repeats (SSRs were identified from 12,000 unigenes. Twenty primer pairs for SSRs were randomly selected for the validation of their amplification effect. Conclusion: RNA-seq data was firstly used to provide a comprehensive gene information on P. ternata at the transcriptional level. These data will advance molecular genetics in this valuable medicinal plant.

  17. Effect of dispersed hydrophilic silicon dioxide nanoparticles on batch adsorption of benzoic acid from aqueous solution using modified natural vermiculite: An equilibrium study

    Directory of Open Access Journals (Sweden)

    Ehsan Sadeghi Pouya

    2016-10-01

    Full Text Available The equilibrium adsorption of benzoic acid from an aqueous medium on a natural vermiculite-based adsorbent was studied in the presence and absence of hydrophilic silicon dioxide nanoparticles in batchwise mode. The adsorbent was prepared through grinding natural vermiculite in a laboratory vibratory disk mill and the surfactant modification of ground vermiculite by cetyltrimethylammonium bromide, subsequently. The equilibrium isotherm in the presence and absence of nanoparticles was experimentally obtained and the equilibrium data were fitted to the Langmuir, Freundlich, Dubinin–Radushkevich and Temkin models. The results indicated that the dispersion of silicon dioxide nanoparticles at optimum concentration in the liquid phase remarkably increases the removal efficiency. Furthermore, it yields a more favorable equilibrium isotherm and changes the compatibility of equilibrium data from the Langmuir and Temkin equations to just the Langmuir equation. A quadratic polynomial model predicting the equilibrium adsorbent capacity in the presence of nanoparticles as a function of the adsorbate and initial nanoparticle concentrations was successfully developed using the response surface methodology based on the rotatable central composite design. A desirability function was used in order to optimize the values of all variables, independent and dependent ones, simultaneously.

  18. Synthesis and spectroscopic characterization on 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid: A DFT approach

    Science.gov (United States)

    Kurt, M.; Sas, E. Babur; Can, M.; Okur, S.; Icli, S.; Demic, S.; Karabacak, M.; Jayavarthanan, T.; Sundaraganesan, N.

    2016-01-01

    A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) 13C NMR and 1H NMR chemical shift values of (TPBA), in the ground state have been calculated by using ab initio density functional theory (DFT/B3LYP) method with 6-311G(d,p) as basis set for the first time. Comparison of the observed fundamental vibrational modes of (TPBA) and calculated results by DFT/B3LYP method indicates that B3LYP level of theory giving yield good results for quantum chemical studies. Vibrational wavenumbers obtained by the DFT/B3LYP method are in good agreement with the experimental data. The study was complemented with a natural bond orbital (NBO) analysis, to evaluate the significance of hyperconjugative interactions and electrostatic effects on such molecular structure. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals analysis and thermodynamic properties of TPBA were investigated using theoretical calculations.

  19. Citric acid cycle in the hyperthermophilic archaeon Pyrobaculum islandicum grown autotrophically, heterotrophically, and mixotrophically with acetate.

    Science.gov (United States)

    Hu, Yajing; Holden, James F

    2006-06-01

    The hyperthermophilic archaeon Pyrobaculum islandicum uses the citric acid cycle in the oxidative and reductive directions for heterotrophic and autotrophic growth, respectively, but the control of carbon flow is poorly understood. P. islandicum was grown at 95 degrees C autotrophically, heterotrophically, and mixotrophically with acetate, H2, and small amounts of yeast extract and with thiosulfate as the terminal electron acceptor. The autotrophic growth rates and maximum concentrations of cells were significantly lower than those in other media. The growth rates on H2 and 0.001% yeast extract with and without 0.05% acetate were the same, but the maximum concentration of cells was fourfold higher with acetate. There was no growth with acetate if 0.001% yeast extract was not present, and addition of H2 to acetate-containing medium greatly increased the growth rates and maximum concentrations of cells. P. islandicum cultures assimilated 14C-labeled acetate in the presence of H2 and yeast extract with an efficiency of 55%. The activities of 11 of 19 enzymes involved in the central metabolism of P. islandicum were regulated under the three different growth conditions. Pyruvate synthase and acetate:coenzyme A (CoA) ligase (ADP-forming) activities were detected only in heterotrophically grown cultures. Citrate synthase activity decreased in autotrophic and acetate-containing cultures compared to the activity in heterotrophic cultures. Acetylated citrate lyase, acetate:CoA ligase (AMP forming), and phosphoenolpyruvate carboxylase activities increased in autotrophic and acetate-containing cultures. Citrate lyase activity was higher than ATP citrate synthase activity in autotrophic cultures. These data suggest that citrate lyase and AMP-forming acetate:CoA ligase, but not ATP citrate synthase, work opposite citrate synthase to control the direction of carbon flow in the citric acid cycle.

  20. Polygenic analysis and targeted improvement of the complex trait of high acetic acid tolerance in the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Meijnen, Jean-Paul; Randazzo, Paola; Foulquié-Moreno, María R; van den Brink, Joost; Vandecruys, Paul; Stojiljkovic, Marija; Dumortier, Françoise; Zalar, Polona; Boekhout, Teun; Gunde-Cimerman, Nina; Kokošar, Janez; Štajdohar, Miha; Curk, Tomaž; Petrovič, Uroš; Thevelein, Johan M

    2016-01-01

    BACKGROUND: Acetic acid is one of the major inhibitors in lignocellulose hydrolysates used for the production of second-generation bioethanol. Although several genes have been identified in laboratory yeast strains that are required for tolerance to acetic acid, the genetic basis of the high acetic

  1. Polygenic analysis and targeted improvement of the complex trait of high acetic acid tolerance in the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Meijnen, Jean-Paul; Randazzo, Paola; Foulquié-Moreno, María R; van den Brink, Joost; Vandecruys, Paul; Stojiljkovic, Marija; Dumortier, Françoise; Zalar, Polona; Boekhout, Teun; Gunde-Cimerman, Nina; Kokošar, Janez; Štajdohar, Miha; Curk, Tomaž; Petrovič, Uroš; Thevelein, Johan M

    2016-01-01

    BACKGROUND: Acetic acid is one of the major inhibitors in lignocellulose hydrolysates used for the production of second-generation bioethanol. Although several genes have been identified in laboratory yeast strains that are required for tolerance to acetic acid, the genetic basis of the high acetic

  2. Batch and continuous culture-based selection strategies for acetic acid tolerance in xylose-fermenting Saccharomyces cerevisiae.

    Science.gov (United States)

    Wright, Jeremiah; Bellissimi, Eleonora; de Hulster, Erik; Wagner, Andreas; Pronk, Jack T; van Maris, Antonius J A

    2011-05-01

    Acetic acid tolerance of Saccharomyces cerevisiae is crucial for the production of bioethanol and other bulk chemicals from lignocellulosic plant-biomass hydrolysates, especially at a low pH. This study explores two evolutionary engineering strategies for the improvement of acetic acid tolerance of the xylose-fermenting S. cerevisiae RWB218, whose anaerobic growth on xylose at pH 4 is inhibited at acetic acid concentrations >1 g L(-1) : (1) sequential anaerobic, batch cultivation (pH 4) at increasing acetic acid concentrations and (2) prolonged anaerobic continuous cultivation without pH control, in which acidification by ammonium assimilation generates selective pressure for acetic acid tolerance. After c. 400 generations, the sequential-batch and continuous selection cultures grew on xylose at pH≤4 with 6 and 5 g L(-1) acetic acid, respectively. In the continuous cultures, the specific xylose-consumption rate had increased by 75% to 1.7 g xylose g(-1) biomass h(-1) . After storage of samples from both selection experiments at -80 °C and cultivation without acetic acid, they failed to grow on xylose at pH 4 in the presence of 5 g L(-1) acetic acid. Characterization in chemostat cultures with linear acetic acid gradients demonstrated an acetate-inducible acetic acid tolerance in samples from the continuous selection protocol.

  3. Pretreatment of corn stover with diluted acetic acid for enhancement of acidogenic fermentation.

    Science.gov (United States)

    Zhao, Xu; Wang, Lijuan; Lu, Xuebin; Zhang, Shuting

    2014-04-01

    A Box-Behnken design of response surface method was used to optimize acetic acid-catalyzed hydrothermal pretreatment of corn stover, in respect to acid concentration (0.05-0.25%), treatment time (5-15 min) and reaction temperature (180-210°C). Acidogenic fermentations with different initial pH and hydrolyzates were also measured to evaluate the optimal pretreatment conditions for maximizing acid production. The results showed that pretreatment with 0.25% acetic acid at 191°C for 7.74 min was found to be the most optimal condition for pretreatment of corn stover under which the production of acids can reach the highest level. Acidogenic fermentation with the hydrolyzate of pretreatment at the optimal condition at the initial pH=5 was shown to be butyric acid type fermentation, producing 21.84 g acetic acid, 7.246 g propionic acid, 9.170 butyric acid and 1.035 g isovaleric acid from 100g of corn stover in 900 g of water containing 2.25 g acetic acid.

  4. Conformational equilibria and large-amplitude motions in dimers of carboxylic acids: rotational spectrum of acetic acid-difluoroacetic acid.

    Science.gov (United States)

    Gou, Qian; Feng, Gang; Evangelisti, Luca; Caminati, Walther

    2014-10-01

    We report the rotational spectra of two conformers of the acetic acid-difluoroacetic acid adduct (CH3COOH-CHF2COOH) and supply information on its internal dynamics. The two conformers differ from each other, depending on the trans or gauche orientation of the terminal -CHF2 group. Both conformers display splittings of the rotational transitions, due to the internal rotation of the methyl group of acetic acid. The corresponding barriers are determined to be V3(trans)=99.8(3) and V3(gauche)=90.5(9) cm(-1) (where V3 is the methyl rotation barrier height). The gauche form displays a further doubling of the rotational transitions, due to the tunneling motion of the -CHF2 group between its two equivalent conformations. The corresponding B2 barrier is estimated to be 108(2) cm(-1). The increase in the distance between the two monomers upon OH→OD deuteration (the Ubbelohde effect) is determined.

  5. Thermal decarboxylation of acetic acid: Implications for origin of natural gas

    Science.gov (United States)

    Kharaka, Y.K.; Carothers, W.W.; Rosenbauer, R.J.

    1983-01-01

    Laboratory experiments on the thermal decarboxylation of solutions of acetic acid at 200??C and 300??C were carried out in hydrothermal equipment allowing for on-line sampling of both the gas and liquid phases for chemical and stable-carbon-isotope analyses. The solutions had ambient pH values between 2.5 and 7.1; pH values and the concentrations of the various acetate species at the conditions of the experiments were computed using a chemical model. Results show that the concentrations of acetic acid, and not total acetate in solution, control the reaction rates which follow a first order equation based on decreasing concentrations of acetic acid with time. The decarboxylation rates at 200??C (1.81 ?? 10-8 per second) and 300??C (8.17 ?? 10-8 per second) and the extrapolated rates at lower temperatures are relatively high. The activation energy of decarboxylation is only 8.1 kcal/mole. These high decarboxylation rates, together with the distribution of short-chained aliphatic acid anions in formation waters, support the hypothesis that acid anions are precursors for an important portion of natural gas. Results of the ??13C values of CO2, CH4, and total acetate show a reasonably constant fractionation factor of about 20 permil between CO2 and CH4 at 300??C. The ??13C values of CO2 and CH4 are initially low and become higher as decarboxylation increases. ?? 1983.

  6. Performance of dairy cows fed high levels of acetic acid or ethanol.

    Science.gov (United States)

    Daniel, J L P; Amaral, R C; Sá Neto, A; Cabezas-Garcia, E H; Bispo, A W; Zopollatto, M; Cardoso, T L; Spoto, M H F; Santos, F A P; Nussio, L G

    2013-01-01

    Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7 wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9 kg/d) than those fed the control (35.8 kg/d) or acetic acid (35.3 kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6 kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and γ-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be

  7. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    Science.gov (United States)

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed.

  8. Microbiological preservation of cucumbers for bulk storage using acetic acid and food preservatives.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2008-08-01

    Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to ensure preservation were low enough so that stored cucumbers could be converted to the finished product without the need to wash out and discard excess acid or preservative. Since no thermal process was required, this method of preservation would be applicable for storing cucumbers in bulk containers. Acid tolerant pathogens died off in less than 24 h with the pH, acetic acid, and sodium benzoate concentrations required to assure the microbial stability of cucumbers stored at 30 degrees C. Potassium sorbate as a preservative in this application was not effective. Yeast growth was observed when sulfite was used as a preservative.

  9. Physiological responses of insects to microbial fermentation products: Insights from the interactions between Drosophila and acetic acid.

    Science.gov (United States)

    Kim, Geonho; Huang, Jia Hsin; McMullen, John G; Newell, Peter D; Douglas, Angela E

    2017-05-15

    Acetic acid is a fermentation product of many microorganisms, including some that inhabit the food and guts of Drosophila. Here, we investigated the effect of dietary acetic acid on oviposition and larval performance of Drosophila. At all concentrations tested (0.34-3.4%), acetic acid promoted egg deposition by mated females in no-choice assays; and females preferred to oviposit on diet with acetic acid relative to acetic acid-free diet. However, acetic acid depressed larval performance, particularly extending the development time of both larvae colonized with the bacterium Acetobacter pomorum and axenic (microbe-free) larvae. The larvae may incur an energetic cost associated with dissipating the high acid load on acetic acid-supplemented diets. This effect was compounded by suppressed population growth of A. pomorum on the 3.4% acetic acid diet, such that the gnotobiotic Drosophila on this diet displayed traits characteristic of axenic Drosophila, specifically reduced developmental rate and elevated lipid content. It is concluded that acetic acid is deleterious to larval Drosophila, and hypothesized that acetic acid may function as a reliable cue for females to oviposit in substrates bearing microbial communities that promote larval nutrition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Steam Reforming of Acetic Acid over Co-supported Catalysts: Coupling Ketonization for Greater Stability

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Stephen D.; Spies, Kurt A.; Mei, Donghai; Kovarik, Libor; Kutnyakov, Igor V.; Li, Xiaohong S.; Dagle, Vanessa; Albrecht, Karl O.; Dagle, Robert A.

    2017-09-11

    We report on the markedly improved stability of a novel 2-bed catalytic system, as compared to a conventional 1-bed steam reforming catalyst, for the production of H2 from acetic acid. The 2-bed catalytic system comprises of i) a basic oxide ketonization catalyst for the conversion of acetic acid to acetone, and a ii) Co-based steam reforming catalyst, both catalytic beds placed in sequence within the same unit operation. Steam reforming catalysts are particularly prone to catalytic deactivation when steam reforming acetic acid, used here as a model compound for the aqueous fraction of bio-oil. Catalysts comprising MgAl2O4, ZnO, CeO2, and activated carbon (AC) both with and without Co-addition were evaluated for conversion of acetic acid and acetone, its ketonization product, in the presence of steam. It was found that over the bare oxide support only ketonization activity was observed and coke deposition was minimal. With addition of Co to the oxide support steam reforming activity was facilitated and coke deposition was significantly increased. Acetone steam reforming over the same Co-supported catalysts demonstrated more stable performance and with less coke deposition than with acetic acid feedstock. DFT analysis suggests that over Co surface CHxCOO species are more favorably formed from acetic acid versus acetone. These CHxCOO species are strongly bound to the Co catalyst surface and could explain the higher propensity for coke formation from acetic acid. Based on these findings, in order to enhance stability of the steam reforming catalyst a dual-bed (2-bed) catalyst system was implemented. Comparing the 2-bed and 1-bed (Co-supported catalyst only) systems under otherwise identical reaction conditions the 2-bed demonstrated significantly improved stability and coke deposition was decreased by a factor of 4.

  11. Oral Administration of Lipopolysaccharide of Acetic Acid Bacteria Protects Pollen Allergy in a Murine Model.

    Science.gov (United States)

    Amano, Satoko; Inagawa, Hiroyuki; Nakata, Yoko; Ohmori, Masaki; Kohchi, Chie; Soma, Gen-Ichiro

    2015-08-01

    Lipopolysaccharide (LPS), a major component of the cell wall of Gram-negative bacteria, is known to possess strong immune-regulatory activity. We have found and reported the existence of biologically-active LPS in acetic acid bacteria. The LPS shows Limulus-positive activity and activation of macrophages to produce nitric oxide and tumor necrosis factor. In this study, we investigated the anti-allergic effect of an orally-administrated acetic acid bacteria extract containing LPS; the cedar pollinosis model was used. Acetic acid bacteria were isolated from various fruits by Nodai kaihen medium. Then, the anti-allergic effect of acetic acid bacteria extracts was investigated. BALB/c mice were immunized with a mixture of cedar pollen and alum into their peritoneal cavity; they also received additional immunizations of pollen to nasal cavity. After immunizing the mice with pollen into their nasal cavity to trigger an allergic reaction, the frequency of nose scratching was counted for 5 min. The bacteria were cultured and prepared and the water-extract contained about 1-10 mg/ml of Limulus positive substances. The extract of acetic acid bacteria induced higher levels of interleukin (IL)-10 and FOXP3 mRNA expression in macrophages (RAW246.7 cell), as assessed by DNA microarray analysis. Oral administration of the acetic acid bacteria extract demonstrated significantly less scratching numbers than control water group with pollen immunization. These results showed that LPS in acetic acid bacteria has the potential to protect from an allergic reaction, especially from cedar pollinosis. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  12. Effect of acetic acid on rice seeds coated with rice husk ash

    Directory of Open Access Journals (Sweden)

    Lizandro Ciciliano Tavares

    2013-06-01

    Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

  13. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance.

  14. Acetic acid production from marine algae. Progress report No. 2, September 30--December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicate that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ were observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate. Work is continuing to improve the yield of acetic acid from marine algae. Marine algae have been found to be rather low in carbon, but the carbon appears to be readily available for fermentation. It, therefore, lends itself to the production of higher value chemicals in relatively expensive equipment, where the rapid conversion rate is particularly cost effective. Fixed packed bed fermenters appear to be desirable for the production of liquid products which are inhibitory to the fermentation from coarse substrates. The inhibitory products may be removed from the fermentation by extraction during recirculation. This technique lends itself to either conventional processing or low capital processing of substrates which require long retention times.

  15. Aversive responses by shore crabs to acetic acid but not to capsaicin.

    Science.gov (United States)

    Elwood, Robert W; Dalton, Natasha; Riddell, Gillian

    2017-07-01

    Nociception is the ability to encode and perceive harmful stimuli and allows for a rapid reflexive withdrawal. In some species, nociception might be accompanied by a pain experience, which is a negative feeling that allows for longer-term changes in behaviour. Different types of stimuli may affect nociceptors, but in crustaceans there is conflicting evidence about the ability to respond to chemical stimuli. This study attempts to resolve this situation by testing behavioural responses of the common shore crab, Carcinus maenas, to two chemical irritants frequently used in vertebrate pain studies (acetic acid and capsaicin). In our first experiment acetic acid, water, capsaicin or mineral oil were applied by brush to the mouth, and in a second experiment treatments were applied to the eyes. Application of acetic acid had a marked effect on behaviour that included vigorous movement of mouth parts, scratching at the mouth with the claws and attempts to escape from the enclosure. Acetic acid also caused holding down of the acid-treated eye in the socket. By contrast, capsaicin had no effect and was no different to the control treatment of mineral oil and water. These results demonstrate responsiveness to acetic acid and thus nociceptive capacity for at least some chemicals. Further, the responses that persist after application were consistent with the idea of pain, however, proof of pain is not possible in any animal. Copyright © 2017. Published by Elsevier B.V.

  16. Laboratory Studies of the Tropospheric Loss Processes for Acetic and Peracetic Acid

    Science.gov (United States)

    Orlando, J. J.; Tyndall, G. S.

    2002-12-01

    Organic acids are ubiquitous components of tropospheric air and contribute to acid precipitation, particularly in remote regions. These species are present in the troposphere as the result of direct emissions from anthropogenic and biogenic sources, and as the result of photochemical processing of hydrocarbons. Production of organic acids can occur following ozonolysis of unsaturated hydrocarbons, while both organic acids and peroxyacids are formed from the reactions of HO2 with acylperoxy radicals. For example, both acetic and peracetic acid are known products of the reaction of HO2 with acetylperoxy radicals. In this paper, data relevant to the gas-phase tropospheric destruction of both acetic and peracetic acid are reported, including studies of their UV absorption spectra and of their rate coefficients for reaction with OH radicals. The data, the first of their kind for peracetic acid, show that the gas-phase lifetime of this species will be on the order of 10 days, with OH reaction occurring more rapidly than photolysis. Data on the rate coefficient for reaction of OH with acetic acid appear to resolve some conflicting data in the previous literature, and show 1) that reaction of OH with the acetic acid dimer is slow compared to the monomer and 2) that the rate coefficient possesses a negative temperature dependence near room temperature.

  17. Photophysical properties and excited state intramolecular proton transfer in 2-hydroxy-5-[(E)-(4-methoxyphenyl)diazenyl]benzoic acid in homogeneous solvents and micro-heterogeneous environments

    Energy Technology Data Exchange (ETDEWEB)

    Gashnga, Pynsakhiat Miki [Centre for Advanced Studies, Department of Chemistry, North-Eastern Hill University, Shillong 793022, Meghalaya (India); Singh, T. Sanjoy [Department of Chemistry, Assam University, Silchar 788011, Assam (India); Baul, Tushar S. Basu [Centre for Advanced Studies, Department of Chemistry, North-Eastern Hill University, Shillong 793022, Meghalaya (India); Mitra, Sivaprasad, E-mail: smitra@nehu.ac.in [Centre for Advanced Studies, Department of Chemistry, North-Eastern Hill University, Shillong 793022, Meghalaya (India)

    2014-04-15

    A systematic study on the photophysical properties and excited state intramolecular proton transfer (ESIPT) behavior of 2-hydroxy-5-[(E)-(4-methoxyphenyl)diazenyl]benzoic acid, is reported using steady-state and time-resolved fluorescence spectroscopy in homogeneous solvents as well as in different micro-heterogeneous environments. Depending on the nature of intramolecular hydrogen bond (IHB), the salicylic acid derivative may exist in two different ground state conformers (I and II). Structure I having IHB between the carbonyl oxygen and phenolic hydrogen can undergo ESIPT upon excitation as evidenced by largely Stokes-shifted fluorescence at ∼455 nm; whereas, normal fluorescence in the blue side of the spectrum (∼410 nm) is due to the spontaneous emission from conformer II. The results in homogeneous solvents were compared with those in bio-mimicking environments of β-cyclodextrin (CD) and surfactants. The intensity of the ESIPT fluorescence increases substantially upon encapsulation of the probe into the cyclodextrin as well as micellar nano-cavities. Detailed analysis of the spectroscopic data indicates that the probe forms 1:1 complex with CD in aqueous medium. Binding constant of the probe with the micelles as well as critical micelle concentration was obtained from the variation of fluorescence intensity on increasing concentration of different surfactants in aqueous medium. -- Highlights: • Steady state and time resolved fluorescence study on ESIPT in HMBA. • Dual fluorescence corresponding to the pro- and non-ESIPT structures. • Modulation of ESIPT fluorescence in micro-heterogeneous environments. • 1:1 stoichiometry for interaction with cyclodextrin. • Calculation of binding constant and other physico-chemical properties from fluorescence titration data in surfactants.

  18. Functionalization of chitosan with 3-nitro-4-amino benzoic acid moiety and its application to the collection/concentration of molybdenum in environmental water samples.

    Science.gov (United States)

    Sabarudin, Akhmad; Oshima, Mitsuko; Noguchi, Osamu; Motomizu, Shoji

    2007-10-31

    A chitosan resin functionalized with 3-nitro-4-amino benzoic acid moiety (CCTS-NABA resin) was newly synthesized for the collection/concentration of trace molybdenum by using cross-linked chitosan (CCTS) as base material. The carboxyl group of the moiety was chemically attached to amino group of cross-linked chitosan through amide bond formation. The adsorption behavior of molybdenum as well as other 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution of the elements collected on the resin with 1M HNO(3), the eluates were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). The CCTS-NABA resin can adsorb several metal ions, such as vanadium, gallium, arsenic, selenium, silver, bismuth, thorium, tungsten, tin, tellurium, copper, and molybdenum at appropriate pHs. Among these metal ions, only molybdenum could be adsorbed almost completely on the resin at acidic regions. An excellent selectivity toward molybdenum could be obtained at pH 3-4. The adsorption capacity of CCTS-NABA resin for Mo(VI) was 380mgg(-1) resin. Through the column pretreatment, alkali and alkaline earth metals in river water and seawater samples were successfully removed. The CCTS-NABA resin was applied to the adsorption/collection of molybdenum in river water and seawater samples. The concentrations of molybdenum in river water samples were found in the range of 0.84 and 0.95ppb (ngg(-1)), whereas molybdenum in seawater was about 9ppb. The validation of the proposed method was carried out by determining molybdenum in the certified reference materials of SLRS-4, CASS-4, and NASS-5 after passing through the CCTS-NABA resin; the results showed good agreement with the certified values.

  19. A laboratory study of the effect of acetic acid vapor on atmospheric copper corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Delgado, A.; Cano, E.; Bastidas, J.M.; Lopez, F.A. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain)

    1998-12-01

    A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm{sup 2} day. The corrosion-product layers were characterized using electrochemical, X-ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite (Cu{sub 2}O), copper acetate hydrate [Cu(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O], and copper hydroxide acetate [Cu{sub 4}(OH)(CH{sub 3}COO){sub 7}{center_dot}2H{sub 2}O]. This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion-product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.

  20. Large prebiotic molecules in space: photo-physics of acetic acid and its isomers

    CERN Document Server

    Puletti, Fabrizio; Mulas, Giacomo; Cecchi-Pestellini, Cesare

    2009-01-01

    An increasing number of large molecules have been positively identified in space. Many of these molecules are of biological interest and thus provide insight into prebiotic organic chemistry in the protoplanetary nebula. Among these molecules, acetic acid is of particular importance due to its structural proximity to glycine, the simplest amino acid. We compute electronic and vibrational properties of acetic acid and its isomers, methyl formate and glycolaldehyde, using density functional theory. From computed photo-absorption cross-sections, we obtain the corresponding photo-absorption rates for solar radiation at 1 AU and find them in good agreement with previous estimates. We also discuss glycolaldehyde diffuse emission in Sgr B2(N), as opposite to emissions from methyl formate and acetic acid that appear to be concentrate in the compact region Sgr B2(N-LMH).

  1. Gastroprotective Properties of Manganese Chloride on Acetic Acid ...

    African Journals Online (AJOL)

    Dr Olaleye

    factors causes ulcer, gastric acid secretion still remains an important factor in ... acid hyper secretion can also cause problems such as ... and many diseases including osteoporosis, ..... amount of manganese delivered in children's parenteral.

  2. The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

    Directory of Open Access Journals (Sweden)

    Fernando Rodrigues

    Full Text Available Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2, C(3 and C(4. The incorporation of [U-(14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  3. Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum

    DEFF Research Database (Denmark)

    Egebo, L A; Nielsen, S V; Jochimsen, B U

    1991-01-01

    Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires...... an oxygen-consuming opening of the indole ring analogous to the one catalyzed by tryptophan 2,3-dioxygenase. The pattern of metabolite usage by known tryptophan-auxotrophic mutants and studies of metabolites by high-performance liquid chromatography indicate that anthranilic acid is a terminal degradation...

  4. Enantioselective Additions of Boronates to Chromene Acetals Catalyzed by a Chiral Brønsted acid-Lewis acid System

    Science.gov (United States)

    Moquist, Philip N.; Kodama, Tomohiro; Schaus, Scott E.

    2011-01-01

    Chiral α,β-dihydroxy carboxylic acids catalyze the enantioselective addition of alkenyl- and aryl boronates to chromene acetals. The optimal carboxylic acid is a tartaric acid amide, easily synthesized via a 3-step procedure. The reaction is enhanced by the addition of Lanthanide triflate salts such as cerium(IV)-and ytterbium(III) triflate. The chiral Brønsted acid and metal Lewis acid may be used in as low as 5 mol % relative to acetal substrate. Optimization of the reaction conditions can lead to yields >70% and enantiomeric ratios as high as 99:1. Spectroscopic and kinetic mechanistic studies demonstrate an exchange process leading to a reactive dioxoborolane intermediate leading to enantioselective addition to the pyrylium generated from the chromene acetal. PMID:20721997

  5. The role of glass composition in the behaviour of glass acetic acid and glass lactic acid cements.

    Science.gov (United States)

    Shahid, Saroash; Billington, R W; Pearson, G J

    2008-02-01

    Cements have recently been described, made from glass ionomer glass reacted with acetic and lactic acid instead of polymeric carboxylic acid. From their behaviour a theory relating to a possible secondary setting mechanism of glass ionomer has been adduced. However, only one glass (G338) was used throughout. In this study a much simpler glass ionomer glass (MP4) was compared with G338. This produced very different results. With acetic acid G338 formed cement which became resistant to water over a period of hours, as previously reported, MP4 formed cement which was never stable to water. With lactic acid G338 behaved similarly to G338 with acetic acid, again as reported, but MP4 produced a cement which was completely resistant to water at early exposure and unusually became slightly less resistant if exposure was delayed for 6 h or more. These findings indicate that the theories relating to secondary setting in glass ionomer maturation may need revision.

  6. Separation of lactic acid from acetic acid using a four-zone SMB.

    Science.gov (United States)

    Lee, Ho-Joon; Xie, Yi; Koo, Yoon-Mo; Wang, Nien-Hwa Linda

    2004-01-01

    A simulated moving bed (SMB) process has been developed to separate l-(+)-lactic acid from acetic acid, a major impurity in the fermentation broth of Lactobacillus rhamnosus. Poly(4-vinylpyridine) resin (PVP) was selected as the adsorbent. Adsorption isotherms and mass transfer parameters of the organic acids were estimated from single-column frontal tests. Experimental results show that the Langmuir isotherms obtained from the frontal tests can be used in the design of an SMB process to achieve 99.9% purity and over 93% yield of lactic acid. The column profiles and effluent histories, however, deviate from rate model predictions based on the Langmuir isotherms. They agree more closely with the predictions based on a modified Langmuir isotherm for lactic acid. The standing wave design method for systems with modified Langmuir isotherms is developed in this study. Rate model simulations show that the process based on the modified design method can achieve high purity (>99.9%) and high yield (>99.9%). For this nonlinear system, accurate isotherm model and model parameters are needed in the design, and the zone flow rates must be closely monitored and controlled in order to ensure high purity and high yield in the SMB process.

  7. Recovery of arabinan in acetic acid-catalyzed hydrothermal pretreatment on corn stover

    DEFF Research Database (Denmark)

    Xu, Jian; Hedegaard, Mette Christina; Thomsen, Anne Belinda

    2009-01-01

    Acetic acid-catalyzed hydrothermal pretreatment was done on corn stover under 195 °C, 15 min with the acetic acid ranging from 5 × 10−3 to 0.2 g g−1 corn stover. After pretreatment, the water-insoluble solids (WISs) and liquors were collected respectively. Arabinan recoveries from both WIS...... and liquors were investigated. The results indicate that there was no detectable arabinan left in the WIS when the acetic acid of 0.1 and 0.2 g g−1 corn stover were used in the pretreatment. The arabinan contents in the other WISs were not more than 10%. However, the arabinan found in the liquors...... was not covering the amount of arabinan released from the raw corn stover. For the arabinan recovery from liquor fractions, the highest of 43.57% was obtained by the pretreatment of acetic acid of 0.01 g g−1 of corn stover and the lowest was only 26.77% when the acetic acid of 0.2 g g−1 corn stover was used...

  8. Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose

    Directory of Open Access Journals (Sweden)

    Miguel Macías Macías

    2012-12-01

    Full Text Available Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP. To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L.

  9. Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.

    Science.gov (United States)

    Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca; Cocolin, Luca

    2012-03-01

    In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.

  10. Coproduction of acetic acid and electricity by application of microbial fuel cell technology to vinegar fermentation.

    Science.gov (United States)

    Tanino, Takanori; Nara, Youhei; Tsujiguchi, Takuya; Ohshima, Takayuki

    2013-08-01

    The coproduction of a useful material and electricity via a novel application of microbial fuel cell (MFC) technology to oxidative fermentation was investigated. We focused on vinegar production, i.e., acetic acid fermentation, as an initial and model useful material that can be produced by oxidative fermentation in combination with MFC technology. The coproduction of acetic acid and electricity by applying MFC technology was successfully demonstrated by the simultaneous progress of acetic acid fermentation and electricity generation through a series of repeated batch fermentations. Although the production rate of acetic acid was very small, it increased with the number of repeated batch fermentations that were conducted. We obtained nearly identical (73.1%) or larger (89.9%) acetic acid yields than that typically achieved by aerated fermentation (75.8%). The open-cycle voltages measured before and after fermentation increased with the total fermentation time and reached a maximum value of 0.521 V prior to the third batch fermentation. The maximum current and power densities measured in this study (19.1 μA/cm² and 2.47 μW/cm², respectively) were obtained after the second batch fermentation.

  11. The Antibacterial Activity of Acetic Acid against Biofilm-Producing Pathogens of Relevance to Burns Patients.

    Directory of Open Access Journals (Sweden)

    Fenella D Halstead

    Full Text Available Localised infections, and burn wound sepsis are key concerns in the treatment of burns patients, and prevention of colonisation largely relies on biocides. Acetic acid has been shown to have good antibacterial activity against various planktonic organisms, however data is limited on efficacy, and few studies have been performed on biofilms.We sought to investigate the antibacterial activity of acetic acid against important burn wound colonising organisms growing planktonically and as biofilms.Laboratory experiments were performed to test the ability of acetic acid to inhibit growth of pathogens, inhibit the formation of biofilms, and eradicate pre-formed biofilms.Twenty-nine isolates of common wound-infecting pathogens were tested. Acetic acid was antibacterial against planktonic growth, with an minimum inhibitory concentration of 0.16-0.31% for all isolates, and was also able to prevent formation of biofilms (at 0.31%. Eradication of mature biofilms was observed for all isolates after three hours of exposure.This study provides evidence that acetic acid can inhibit growth of key burn wound pathogens when used at very dilute concentrations. Owing to current concerns of the reducing efficacy of systemic antibiotics, this novel biocide application offers great promise as a cheap and effective measure to treat infections in burns patients.

  12. Effect of Hetero Atom on the Hammett’s Reaction Constant (ρ from the Physical Basis of Dissociation Equilibriums of (Dithio Benzoic Acids and (Thio Phenols and Its Application to Solvolysis Reactions and Some Free Radical Reactions

    Directory of Open Access Journals (Sweden)

    Jagannadham Vandanapu

    2012-01-01

    Full Text Available The emergence of putative Hammett equation in mid 1930s was a boon to physical-organic chemists to elucidate the reaction mechanisms of several organic reactions. Based on the concept of this equation several hundreds of papers have emerged in chemical literature in the last century on the effect of structure, on reactivity, and very few on thermodynamic stability and kinetic reactivity of intermediates. In this article an attempt is made to explain the effect of hetero atom on Hammett’s reaction constant (ρ taking the dissociation equilibriums of benzoic acids, dithiobenzoic acids, phenols, and thiophenols.

  13. Mechanistic Insights Underlying Tolerance to Acetic Acid Stress in Vaginal Candida glabrata Clinical Isolates

    Science.gov (United States)

    Cunha, Diana V.; Salazar, Sara B.; Lopes, Maria M.; Mira, Nuno P.

    2017-01-01

    During colonization of the vaginal tract Candida glabrata cells are challenged with the presence of acetic acid at a low pH, specially when dysbiosis occurs. To avoid exclusion from this niche C. glabrata cells are expected to evolve efficient adaptive responses to cope with this stress; however, these responses remain largely uncharacterized, especially in vaginal strains. In this work a cohort of 18 vaginal strains and 2 laboratory strains (CBS138 and KUE100) were phenotyped for their tolerance against inhibitory concentrations of acetic acid at pH 4. Despite some heterogeneity has been observed among the vaginal strains tested, in general these strains were considerably more tolerant to acetic acid than the laboratory strains. To tackle the mechanistic insights behind this differential level of tolerance observed, a set of vaginal strains differently tolerant to acetic acid (VG281∼VG49 < VG99 < VG216) and the highly susceptible laboratory strain KUE100 were selected for further studies. When suddenly challenged with acetic acid the more tolerant vaginal strains exhibited a higher activity of the plasma membrane proton pump CgPma1 and a reduced internal accumulation of the acid, these being two essential features to maximize tolerance. Based on the higher level of resistance exhibited by the vaginal strains against the action of a β-1,3-glucanase, it is hypothesized that the reduced internal accumulation of acetic acid inside these strains may originate from them having a different cell wall structure resulting in a reduced porosity to undissociated acetic acid molecules. Both the vaginal and the two laboratory strains were found to consume acetic acid in the presence of glucose indicating that metabolization of the acid is used by C. glabrata species as a detoxification mechanism. The results gathered in this study advance the current knowledge on the mechanisms underlying the increased competitiveness of C. glabrata in the vaginal tract, a knowledge that can

  14. Manganese [III] Tetrakis [5,10,15,20]-Benzoic Acid Porphyrin Reduces Adiposity and Improves Insulin Action in Mice with Pre-Existing Obesity.

    Directory of Open Access Journals (Sweden)

    Jonathan R Brestoff

    Full Text Available The superoxide dismutase mimetic manganese [III] tetrakis [5,10,15,20]-benzoic acid porphyrin (MnTBAP is a potent antioxidant compound that has been shown to limit weight gain during short-term high fat feeding without preventing insulin resistance. However, whether MnTBAP has therapeutic potential to treat pre-existing obesity and insulin resistance remains unknown. To investigate this, mice were treated with MnTBAP or vehicle during the last five weeks of a 24-week high fat diet (HFD regimen. MnTBAP treatment significantly decreased body weight and reduced white adipose tissue (WAT mass in mice fed a HFD and a low fat diet (LFD. The reduction in adiposity was associated with decreased caloric intake without significantly altering energy expenditure, indicating that MnTBAP decreases adiposity in part by modulating energy balance. MnTBAP treatment also improved insulin action in HFD-fed mice, a physiologic response that was associated with increased protein kinase B (PKB phosphorylation and expression in muscle and WAT. Since MnTBAP is a metalloporphyrin molecule, we hypothesized that its ability to promote weight loss and improve insulin sensitivity was regulated by heme oxygenase-1 (HO-1, in a similar fashion as cobalt protoporphyrins. Despite MnTBAP treatment increasing HO-1 expression, administration of the potent HO-1 inhibitor tin mesoporphyrin (SnMP did not block the ability of MnTBAP to alter caloric intake, adiposity, or insulin action, suggesting that MnTBAP influences these metabolic processes independent of HO-1. These data demonstrate that MnTBAP can ameliorate pre-existing obesity and improve insulin action by reducing caloric intake and increasing PKB phosphorylation and expression.

  15. Manganese [III] Tetrakis [5,10,15,20]-Benzoic Acid Porphyrin Reduces Adiposity and Improves Insulin Action in Mice with Pre-Existing Obesity.

    Science.gov (United States)

    Brestoff, Jonathan R; Brodsky, Tim; Sosinsky, Alexandra Z; McLoughlin, Ryan; Stansky, Elena; Fussell, Leila; Sheppard, Aaron; DiSanto-Rose, Maria; Kershaw, Erin E; Reynolds, Thomas H

    2015-01-01

    The superoxide dismutase mimetic manganese [III] tetrakis [5,10,15,20]-benzoic acid porphyrin (MnTBAP) is a potent antioxidant compound that has been shown to limit weight gain during short-term high fat feeding without preventing insulin resistance. However, whether MnTBAP has therapeutic potential to treat pre-existing obesity and insulin resistance remains unknown. To investigate this, mice were treated with MnTBAP or vehicle during the last five weeks of a 24-week high fat diet (HFD) regimen. MnTBAP treatment significantly decreased body weight and reduced white adipose tissue (WAT) mass in mice fed a HFD and a low fat diet (LFD). The reduction in adiposity was associated with decreased caloric intake without significantly altering energy expenditure, indicating that MnTBAP decreases adiposity in part by modulating energy balance. MnTBAP treatment also improved insulin action in HFD-fed mice, a physiologic response that was associated with increased protein kinase B (PKB) phosphorylation and expression in muscle and WAT. Since MnTBAP is a metalloporphyrin molecule, we hypothesized that its ability to promote weight loss and improve insulin sensitivity was regulated by heme oxygenase-1 (HO-1), in a similar fashion as cobalt protoporphyrins. Despite MnTBAP treatment increasing HO-1 expression, administration of the potent HO-1 inhibitor tin mesoporphyrin (SnMP) did not block the ability of MnTBAP to alter caloric intake, adiposity, or insulin action, suggesting that MnTBAP influences these metabolic processes independent of HO-1. These data demonstrate that MnTBAP can ameliorate pre-existing obesity and improve insulin action by reducing caloric intake and increasing PKB phosphorylation and expression.

  16. Comparison of the crystal structures of methyl 4-bromo-2-(meth-oxy-meth-oxy)benzoate and 4-bromo-3-(meth-oxy-meth-oxy)benzoic acid.

    Science.gov (United States)

    Suchetan, P A; Suneetha, V; Naveen, S; Lokanath, N K; Krishna Murthy, P

    2016-04-01

    The title compounds, C10H11BrO4, (I), and C9H9BrO4, (II), are derivatives of bromo-hy-droxy-benzoic acids. Compound (II) crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In both (I) and (II), the O-CH2-O-CH3 side chain is not in its fully extended conformation; the O-C-O-C torsion angle is 67.3 (3) ° in (I), and -65.8 (3) and -74.1 (3)° in mol-ecules A and B, respectively, in compound (II). In the crystal of (I), mol-ecules are linked by C-H⋯O hydrogen bonds, forming C(5) chains along [010]. The chains are linked by short Br⋯O contacts [3.047 (2) Å], forming sheets parallel to the bc plane. The sheets are linked via C-H⋯π inter-actions, forming a three-dimensional architecture. In the crystal of (II), mol-ecules A and B are linked to form R 2 (2)(8) dimers via two strong O-H⋯O hydrogen bonds. These dimers are linked into ⋯A-B⋯A-B⋯A-B⋯ [C 2 (2)(15)] chains along [011] by C-H⋯O hydrogen bonds. The chains are linked by slipped parallel π-π inter-actions [inter-centroid distances = 3.6787 (18) and 3.8431 (17) Å], leading to the formation of slabs parallel to the bc plane.

  17. Nonlinear optical studies on 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid thin films deposited by matrix-assisted pulsed laser evaporation (MAPLE)

    Energy Technology Data Exchange (ETDEWEB)

    Matei, Andreea [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Marinescu, Maria, E-mail: maria.marinescu@chimie.unibuc.ro [UB - University of Bucharest, Faculty of Chemistry, 90-92 Şoseaua Panduri, Sector 5, RO-010184, Bucharest (Romania); Constantinescu, Catalin, E-mail: catalin.constantinescu@inflpr.ro [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Ion, Valentin; Mitu, Bogdana [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Ionita, Iulian [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); UB - University of Bucharest, Faculty of Physics, 405 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Dinescu, Maria [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Emandi, Ana [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); UB - University of Bucharest, Faculty of Chemistry, 90-92 Şoseaua Panduri, Sector 5, RO-010184, Bucharest (Romania)

    2016-06-30

    Graphical abstract: - Highlights: • A newly synthesized ferrocene-derivative exhibits SHG potential. • Matrix-assisted pulsed laser evaporation is employed for thin film fabrication. • The optical properties of the films are investigated, presented and discussed. • At maximum laser output power, the SHG signal is strongly influenced by thin film thickness. - Abstract: We present results on a new, laboratory synthesized ferrocene-derivative, i.e. 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid. Thin films with controlled thickness are deposited by matrix-assisted pulsed laser evaporation (MAPLE), on quartz and silicon substrates, with the aim of evaluating the nonlinear optical properties for potential optoelectronic applications. Dimethyl sulfoxide was used as matrix, with 1% wt. concentration of the guest compound. The frozen target is irradiated by using a Nd:YAG laser (4ω/266 nm, 7 ns pulse duration, 10 Hz repetition rate), at low fluences ranging from 0.1 to 1 J/cm{sup 2}. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to probe the surface morphology of the films. Fourier transform infrared (FTIR) and Raman spectroscopy reveal similar structure of the thin film material when compared to the starting material. The optical properties of the thin films are investigated by spectroscopic-ellipsometry (SE), and the refractive index dependence with respect to temperature is studied. The second harmonic generation (SHG) potential is assessed by using a femtosecond Ti:sapphire laser (800 nm, 60–100 fs pulse duration, 80 MHz repetition rate), at 200 mW maximum output power, revealing that the SHG signal intensity is strongly influenced by the films’ thickness.

  18. Synthesis, electrochemical, structural, spectroscopic and biological activities of mixed ligand copper (II) complexes with 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid and nitrogenous bases

    Science.gov (United States)

    Choudhary, Mukesh; Patel, R. N.; Rawat, S. P.

    2014-02-01

    Three new copper (II) complexes viz. [Cu(L1)(bipy)]ṡ2H2O 1, [Cu(L1)(dmp)]ṡCH3CN 2, [Cu(L1)(phen)] 3 where L1H2 = 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid, bipy = 2,2‧-bipyridine; dmp = 2,9-dimethyl 1,10-phenanthroline, phen = 1,10-phenanthroline have been synthesized and characterized by physic-chemical and spectroscopic methods. The solid-state structures of 1 and 2 were determined by single crystal X-ray crystallography, which revealed distorted square pyramidal geometry. In solid-state structure, 1 is self-assembled via intermolecular π…π stacking and the distances between centroids of aromatic ring is 3.525 Å. L1H2 is a diprotic tridentate Schiff base ligand having ONO donor site. Infrared spectra, ligand field spectra and magnetic susceptibility measurements agree with the observed crystal structures. The EPR spectra of these complexes in frozen DMSO solutions showed a single at g ca. 2. The trend in g-value (g|| > g⊥ > 2.0023) suggests that the unpaired electron on copper (II) has d character. Copper (II) complexes 1-3 yielded an irreversible couple corresponding to the Cu (II)/Cu (I) redox process. Superoxide dismutase activity of all these complexes has been revealed to catalyze the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed. Antimicrobial and antifungal activities of these complexes were also investigated.

  19. p-Hydroxy benzoic acid-conjugated dendrimer nanotherapeutics as potential carriers for targeted drug delivery to brain: an in vitro and in vivo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Swami, Rajan; Singh, Indu [National Institute of Pharmaceutical Education & Research (NIPER), Department of Pharmaceutics (India); Kulhari, Hitesh [CSIR-Indian Institute of Chemical Technology, Medicinal Chemistry & Pharmacology Division (India); Jeengar, Manish Kumar [National Institute of Pharmaceutical Education & Research (NIPER), Departmentof Pharmacology (India); Khan, Wahid, E-mail: wahid@niperhyd.ac.in; Sistla, Ramakrishna, E-mail: sistla@iict.res.in, E-mail: rksistla@yahoo.com [National Institute of Pharmaceutical Education & Research (NIPER), Department of Pharmaceutics (India)

    2015-06-15

    Dendrimers which are discrete nanostructures/nanoparticles are emerging as promising candidates for many nanomedicine applications. Ligand-conjugated dendrimer facilitate the delivery of therapeutics in a targeted manner. Small molecules such as p-hydroxyl benzoic acid (pHBA) were found to have high affinity for sigma receptors which are prominent in most parts of central nervous system and tumors. The aim of this study was to synthesize pHBA-dendrimer conjugates as colloidal carrier for site-specific delivery of practically water insoluble drug, docetaxel (DTX) to brain tumors and to determine its targeting efficiency. pHBA, a small molecule ligand was coupled to the surface amine groups of generation 4-PAMAM dendrimer via a carbodiimide reaction and loaded with DTX. The conjugation was confirmed by {sup 1}HNMR and FT-IR spectroscopy. In vitro release of drug from DTX-loaded pHBA-conjugated dendrimer was found to be less as compared to unconjugated dendrimers. The prepared drug delivery system exhibited good physico-chemical stability and decrease in hemolytic toxicity. Cell viability and cell uptake studies were performed against U87MG human glioblastoma cells and formulations exerted considerable anticancer effect than plain drug. Conjugation of dendrimer with pHBA significantly enhanced the brain uptake of DTX which was shown by the recovery of a higher percentage of the dose from the brain following administration of pHBA-conjugated dendrimers compared with unconjugated dendrimer or formulation in clinical use (Taxotere{sup ®}). Therefore, pHBA conjugated dendrimers could be an efficient delivery vehicle for the targeting of anticancer drugs to brain tumors.

  20. Use of pooled sodium acetate acetic acid formalin-preserved fecal specimens for the detection of intestinal parasites.

    Science.gov (United States)

    Gaafar, Maha R

    2011-01-01

    This study aimed at comparing detection of intestinal parasites from single unpreserved stool sample vs. sodium acetate acetic acid formalin (SAF)-preserved pooled samples, and stained with chlorazol black dye in routine practice. Unpreserved samples were collected from 120 patients and represented as Group I. Other three SAF-preserved samples were collected from the same patients over a 6-day period and represented as Groups IIa, IIb, and IIc. The latter groups were equally subdivided into two subgroups. The first subgroup of each of the three samples was examined individually, whereas the second subgroup of each were pooled and examined as a single specimen. All groups were examined by the routine diagnostic techniques; however, in group II when the diagnosis was uncertain, the chlorazol black dye staining procedure was carried out. Results demonstrated that out of 74 patients who continued the study, 12 cases (16%) were positive in group I, compared with 29 (39%) in the subgroups examined individually, and 27 (36%) in the pooled subgroups. Therefore, pooling of preserved fecal samples is an efficient and economical procedure for the detection of parasites. Furthermore, the chlorazol black dye was simple and effective in detecting the nuclear details of different parasites.

  1. Effect of acetic acid on physical properties of pregelatinized wheat and corn starch gels.

    Science.gov (United States)

    Majzoobi, Mahsa; Kaveh, Zahra; Farahnaky, Asgar

    2016-04-01

    Pregelatinized starches are physically modified starches with ability to absorb water and increase viscosity at ambient temperature. The main purpose of this study was to determine how different concentrations of acetic acid (0, 500, 1000, 10,000 mg/kg) can affect functional properties of pregelatinized wheat and corn starches (PGWS and PGCS, respectively) produced by a twin drum drier. With increasing acetic acid following changes occurred for both samples; cold water solubility (at 25 °C) increased, water absorption and apparent cold water viscosity (at 25 °C) reduced, the smooth surface of the starch particles converted to an uneven surface as confirmed by scanning electron microscopy, cohesiveness, consistency and turbidity of the starch gels reduced while their syneresis increased. It was found that in presence of acetic acid, PGWS resulted in higher water absorption and apparent cold water viscosity and produced more cohesive and turbid gels with less syneresis compared to PGCS.

  2. The lifespan-promoting effect of acetic acid and Reishi polysaccharide.

    Science.gov (United States)

    Chuang, Ming-Hong; Chiou, Shyh-Horng; Huang, Chun-Hao; Yang, Wen-Bin; Wong, Chi-Huey

    2009-11-15

    Using Caenorhabditis elegans as a model organism, various natural substances and commercial health-food supplements were screened to evaluate their effects on longevity. Among the substances tested, acetic acid and Reishi polysaccharide fraction 3 (RF3) were shown to increase the expression of the lifespan and longevity-related transcription factor DAF-16 in C. elegans. We have shown that RF3 activates DAF-16 expression via TIR-1 receptor and MAPK pathway whereas acetic acid inhibits the trans-membrane receptor DAF-2 of the insulin/IGF-1 pathway to indirectly activate DAF-16 expression. In addition, a mixture of acetic acid and RF3 possesses a combined effect 30-40% greater than either substance used alone. A proteomic analysis of C. elegans using 2-DE and LC-MS/MS was then carried out, and 15 differentially expressed proteins involved in the lifespan-promoting activity were identified.

  3. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid

    Directory of Open Access Journals (Sweden)

    Sergio eGiannattasio

    2013-02-01

    Full Text Available Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications.

  4. Influence of Acetic Acid on Dynamic Behavior of Hydrolazation and Film Forming of Organosilane

    Institute of Scientific and Technical Information of China (English)

    YANG Lixia; ZHANG Wenguang; GU Tao; FENG Jun

    2009-01-01

    The influence of acetic acid on dynamic behavior of hydrolazation and film forming of an expoxy-silane compound(γ-GPS)was investigated by conductivity meter,IR and AFM.The experimental results show that there is an optimal pH value(pH=4-5)for hydrolysis of silane solution,and with the prolongation of hydrolytic time,the promotion of acetic acid on the hydrolyza-tion of silane solution become more obvious.During the adsorption and film forming process,acetic acid could promote the formation of Si-O-Fe bond,which activates hydroxyl group of silanol unit and facilitates this hydroxyl group to react with adjacent silanol unit forming linear condensation polymers.

  5. Transformation of acetate carbon into carbohydrate and amino acid metabilites during decomposition in soil

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Paul, E. A.

    1971-01-01

    Carbon-14-labelled acetate was added to a heavy clay soil of pH 7.6 to study the transformation of acetate carbon into carbohydrate and amino acid metabolites during decomposition. The acetate was totally metabolized after 6 days of incubation at 25°C when 70% of the labelled carbon had been...... evolved as CO2. Maximum incorporation of trace-C into the various organic fractions was observed after 4 days when 19% of residual, labelled carbon in the soil was located in carbohydrates, 29 % in amino acids and 21 % in the insoluble residue of the soil. The curves showing the amounts of labelled carbon...... located in carbohydrates and amino acid metabolites show a curvilinear form during the first 30 days of incubation, indicating a variety of chemical compounds decaying at different rates. After this time, the decay curves became straight lines indicating a greater homogeneity of the metabolites. After 200...

  6. Acetic acid-catalyzed formation of N-phenylphthalimide from phthalanilic acid: a computational study of the mechanism.

    Science.gov (United States)

    Takahashi, Ohgi; Kirikoshi, Ryota; Manabe, Noriyoshi

    2015-05-28

    In glacial acetic acid, phthalanilic acid and its monosubstituents are known to be converted to the corresponding phthalimides in relatively good yields. In this study, we computationally investigated the experimentally proposed two-step (addition-elimination or cyclization-dehydration) mechanism at the second-order Møller-Plesset perturbation (MP2) level of theory for the unsubstituted phthalanilic acid, with an explicit acetic acid molecule included in the calculations. In the first step, a gem-diol tetrahedral intermediate is formed by the nucleophilic attack of the amide nitrogen. The second step is dehydration of the intermediate to give N-phenylphthalimide. In agreement with experimental findings, the second step has been shown to be rate-determining. Most importantly, both of the steps are catalyzed by an acetic acid molecule, which acts both as proton donor and acceptor. The present findings, along with those from our previous studies, suggest that acetic acid and other carboxylic acids (in their undissociated forms) can catalyze intramolecular nucleophilic attacks by amide nitrogens and breakdown of the resulting tetrahedral intermediates, acting simultaneously as proton donor and acceptor. In other words, double proton transfers involving a carboxylic acid molecule can be part of an extensive bond reorganization process from cyclic hydrogen-bonded complexes.

  7. Recovery of acetic acid from an aqueous pyrolysis oil phase by reactive extraction using tri-n-octylamine

    NARCIS (Netherlands)

    Rasrendra, C. B.; Girisuta, B.; van de Bovenkamp, H. H.; Winkelman, J. G. M.; Leijenhorst, E. J.; Venderbosch, R. H.; Windt, M.; Meier, D.; Heeres, H. J.

    2011-01-01

    The application of reactive extraction to isolate organic acids, particularly acetic acid, from the aqueous stream of phase splitted pyrolysis oil using a long chain aliphatic tertiary amine is reported. Acetic acid recovery was optimized by selecting the proper amine and diluent combination and adj

  8. Recovery of acetic acid from an aqueous pyrolysis oil phase by reactive extraction using tri-n-octylamine

    NARCIS (Netherlands)

    Rasrendra, C. B.; Girisuta, B.; van de Bovenkamp, H. H.; Winkelman, J. G. M.; Leijenhorst, E. J.; Venderbosch, R. H.; Windt, M.; Meier, D.; Heeres, H. J.

    2011-01-01

    The application of reactive extraction to isolate organic acids, particularly acetic acid, from the aqueous stream of phase splitted pyrolysis oil using a long chain aliphatic tertiary amine is reported. Acetic acid recovery was optimized by selecting the proper amine and diluent combination and

  9. Recovery of acetic acid from an aqueous pyrolysis oil phase by reactive extraction using tri-n-octylamine

    NARCIS (Netherlands)

    Rasrendra, C. B.; Girisuta, B.; van de Bovenkamp, H. H.; Winkelman, J. G. M.; Leijenhorst, E. J.; Venderbosch, R. H.; Windt, M.; Meier, D.; Heeres, H. J.

    2011-01-01

    The application of reactive extraction to isolate organic acids, particularly acetic acid, from the aqueous stream of phase splitted pyrolysis oil using a long chain aliphatic tertiary amine is reported. Acetic acid recovery was optimized by selecting the proper amine and diluent combination and adj

  10. Differentiation between stoichiometric and anticatalytic antioxidant properties of benzoic acid analogues: a structure/redox potential relationship study.

    Science.gov (United States)

    Franck, Thierry; Mouithys-Mickalad, Ange; Robert, Thierry; Ghitti, Gianangelo; Deby-Dupont, Ginette; Neven, Philippe; Serteyn, Didier

    2013-11-25

    We investigated the antioxidant activities of some phenolic acid derivatives on a cell free system and on cellular and enzymatic models involved in inflammation. The stoichiometric antioxidant activities of phenolic acid derivatives were studied by measuring their capacity to scavenge the radical cation 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS(+)) and reactive oxygen species (ROS) produced by stimulated neutrophils. The anticatalytic antioxidant capacity of the molecules was evaluated on the activity of myeloperoxidase (MPO), an oxidant enzyme present in and released by the primary granules of neutrophils. The ROS produced by PMA-stimulated neutrophils were measured by lucigenin-enhanced chemiluminescence (CL) and the potential interaction of the molecules with MPO was investigated without interferences due to medium by Specific Immuno-Extraction Followed by Enzyme Detection (SIEFED). The antioxidant activities of the phenolic compounds were correlated to their redox potentials measured by differential pulse voltammetry (DPV), and discussed in relation to their molecular structure. The ability of the phenolic molecules to scavenge ABTS radicals and ROS derived from neutrophils was inversely correlated to their increased redox potential. The number of hydroxyl groups (three) and their position (catechol) were essential for their efficacy as stoichiometric antioxidants or scavengers. On MPO activity, the inhibitory capacity of the molecules was not really correlated with their redox potential. Likewise, for the inhibition of MPO activity the number of OH groups and mainly the elongation of the carboxylic group were essential, probably by facilitating the interaction with the active site or the structure of the enzyme. The redox potential measurement, combined with ABTS and CL techniques, seems to be a good technique to select stoichiometric antioxidants but not anticatalytic ones, as seen for MPO, what rather involves a direct interaction with

  11. [Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

    Science.gov (United States)

    Kai, Xia; Xinle, Liang; Yudong, Li

    2015-12-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria.

  12. Effect of acetic acid on optical coherence tomography (OCT) images of cervical epithelium.

    Science.gov (United States)

    Gallwas, Julia; Stanchi, Anna; Dannecker, Christian; Ditsch, Nina; Mueller, Susanna; Mortensen, Uwe; Stepp, Herbert

    2014-11-01

    Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in the identification of precancerous and cancerous cervical lesions. The purpose of this study was to investigate the effect of acetic acid on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 3 and 10 min after application of 6 % acetic acid. A corresponding histology was obtained from all sites. The images taken 3 and 10 min after application of acetic acid were compared to the initial images with respect to changes in brightness, contrast, and scanning depth employing a standard nonparametric test of differences of proportions. Further, mean intensity backscattering curves were calculated from all OCT images in the histological groups CIN3, inflammation, or normal epithelium. Mean difference profiles within each of these groups were determined, reflecting the mean differences between the condition before application of acetic acid and the exposure times 3 and 10 min, respectively. According to the null hypothesis, the difference profiles do not differ from profiles fluctuating around zero in a stationary way, which implies that the profiles do not differ significantly from each other. The null hypothesis was tested employing the KPSS test. The visual analysis of 137 OCT images from 46 sites of 10 conization specimens revealed a statistically significant increase in brightness for all three groups and a statistically significant decrease in contrast for normal epithelium after 10 min. Further, an increase in scanning depth was noted for normal epithelium after 10 min and for CIN3 after 3 min. The analysis of mean intensity profiles showed an increased backscattering intensity after application of acetic acid. Acetic acid significantly affects the quality of OCT images. Overall brightness and scanning depth increase with the opposite effect regarding the image contrast. Whether the observed changes

  13. Inhibition of microbial xylitol production by acetic acid and its relation with fermentative parameters.

    Science.gov (United States)

    Morita, T A; Silva, S S

    2000-01-01

    Precipitated sugarcane bagasse hemicellulosic hydrolysate containing acetic acid was fermented by Candida guilliermondii FTI20037 under different operational conditions (pH 4.0 and 7.0, three aeration rates). At pH 7.0 and kLa of 10 (0.75 vvm) and 22.5/h (3.0 vvm) the acetic acid had not been consumed until the end of the fermentations, whereas at the same pH and kLa of 35/h (4.5 vvm) the acid was rapidly consumed and acetic acid inhibition was not important. On the other hand, fermentations at an initial pH of 4.0 and kLa of 22.5 and 35/h required less time for the acid uptake than fermentations at kLa of 10/h. The acetic acid assimilation by the yeast indicates the ability of this strain to ferment in partially detoxified medium, making possible the utilization of the sugarcane bagasse hydrolysate in this bio-process. The effects on xylitol yield and production are reported.

  14. Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella

    Directory of Open Access Journals (Sweden)

    Rao Z. Abbas

    2011-02-01

    Full Text Available The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations (1%, 2% and 3% of acetic acid and amproilum (at the dose rate of 125ppm were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio and pathogenic (oocyst score, lesion score and mortality %age parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.

  15. 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...

  16. Isolation and characterization of esters of indole-3-acetic acid from the liquid endosperm of the horse chestnut (Aesculus species)

    Science.gov (United States)

    Domagalski, W.; Schulze, A.; Bandurski, R. 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.

  17. Effect of acetic acid in recycling water on ethanol production for cassava in an integrated ethanol-methane fermentation process.

    Science.gov (United States)

    Yang, Xinchao; Wang, Ke; Zhang, Jianhua; Tang, Lei; Mao, Zhonggui

    2016-11-01

    Recently, the integrated ethanol-methane fermentation process has been studied to prevent wastewater pollution. However, when the anaerobic digestion reaction runs poorly, acetic acid will accumulate in the recycling water. In this paper, we studied the effect of low concentration of acetic acid (≤25 mM) on ethanol fermentation at different initial pH values (4.2, 5.2 or 6.2). At an initial pH of 4.2, ethanol yields increased by 3.0% and glycerol yields decreased by 33.6% as the acetic acid concentration was increased from 0 to 25 mM. Raising the concentration of acetic acid to 25 mM increased the buffering capacity of the medium without obvious effects on biomass production in the cassava medium. Acetic acid was metabolized by Saccharomyces cerevisiae for the reason that the final concentration of acetic acid was 38.17% lower than initial concentration at pH 5.2 when 25 mM acetic acid was added. These results confirmed that a low concentration of acetic acid in the process stimulated ethanol fermentation. Thus, reducing the acetic acid concentration to a controlled low level is more advantageous than completely removing it.

  18. A new laboratory evolution approach to select for constitutive acetic acid tolerance in Saccharomyces cerevisiae and identification of causal mutations.

    Science.gov (United States)

    González-Ramos, Daniel; Gorter de Vries, Arthur R; Grijseels, Sietske S; van Berkum, Margo C; Swinnen, Steve; van den Broek, Marcel; Nevoigt, Elke; Daran, Jean-Marc G; Pronk, Jack T; van Maris, Antonius J A

    2016-01-01

    Acetic acid, released during hydrolysis of lignocellulosic feedstocks for second generation bioethanol production, inhibits yeast growth and alcoholic fermentation. Yeast biomass generated in a propagation step that precedes ethanol production should therefore express a high and constitutive level of acetic acid tolerance before introduction into lignocellulosic hydrolysates. However, earlier laboratory evolution strategies for increasing acetic acid tolerance of Saccharomyces cerevisiae, based on prolonged cultivation in the presence of acetic acid, selected for inducible rather than constitutive tolerance to this inhibitor. Preadaptation in the presence of acetic acid was shown to strongly increase the fraction of yeast cells that could initiate growth in the presence of this inhibitor. Serial microaerobic batch cultivation, with alternating transfers to fresh medium with and without acetic acid, yielded evolved S. cerevisiae cultures with constitutive acetic acid tolerance. Single-cell lines isolated from five such evolution experiments after 50-55 transfers were selected for further study. An additional constitutively acetic acid tolerant mutant was selected after UV-mutagenesis. All six mutants showed an increased fraction of growing cells upon a transfer from a non-stressed condition to a medium containing acetic acid. Whole-genome sequencing identified six genes that contained (different) mutations in multiple acetic acid-tolerant mutants. Haploid segregation studies and expression of the mutant alleles in the unevolved ancestor strain identified causal mutations for the acquired acetic acid tolerance in four genes (ASG1, ADH3, SKS1 and GIS4). Effects of the mutations in ASG1, ADH3 and SKS1 on acetic acid tolerance were additive. A novel laboratory evolution strategy based on alternating cultivation cycles in the presence and absence of acetic acid conferred a selective advantage to constitutively acetic acid-tolerant mutants and may be applicable for

  19. Production of oils from acetic acid by the oleaginous yeast Cryptococcus curvatus.

    Science.gov (United States)

    Christophe, G; Deo, J Lara; Kumar, V; Nouaille, R; Fontanille, P; Larroche, C

    2012-07-01

    The feasibility of the conversion of acetic acid, a metabolite commonly obtained during anaerobic fermentation processes, into oils using the yeast Cryptococcus curvatus was reported. This microorganism exhibited very slow growth rates on acetate as carbon source, which led to design a two-stage cultivation process. The first consisted of cell growth on glucose as carbon source until its complete exhaustion. The second step involved the use of acetate as carbon source under nitrogen limitation in order to induce lipid accumulation. A typical experiment performed in a bioreactor involved a preliminary yeast growth with a glucose initial concentration of 15 g/L glucose. Further additions of acetate and nitrogen source allowed a final lipid accumulation up to 50% (w/w). These promising results demonstrated the suitability of the technique proposed.

  20. Recovery of Acetic Acid from An Ethanol Fermentation Broth by Liquid-Liquid Extraction (LLE) Using Various Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thu Huong; Kim, Tae Hyun [Kongju National University, Cheonan (Korea, Republic of); Um, Byung Hwan [Hankyong National University, Anseong (Korea, Republic of)

    2015-12-15

    Liquid-liquid extraction (LLE) using various solvents was studied for recovery of acetic acid from a synthetic ethanol fermentation broth. The microbial fermentation of sugars presented in hydrolyzate gives rise to acetic acid as a byproduct. In order to obtain pure ethanol for use as a biofuel, fermentation broth should be subjected to acetic acid removal step and the recovered acetic acid can be put to industrial use. Herein, batch LLE experiments were carried out at 25°C using a synthetic fermentation broth comprising 20.0 g l{sup -1} acetic acid and 5.0 g l{sup -1} ethanol. Ethyl acetate (EtOAc), tri-n-octylphosphine oxide (TOPO), tri-n-octylamine (TOA), and tri-n-alkylphosphine oxide (TAPO) were utilized as solvents, and the extraction potential of each solvent was evaluated by varying the organic phase-to-aqueous phase ratios as 0.2, 0.5, 1.0, 2.0, and 4.0. The highest acetic acid extraction yield was achieved with TAPO; however, the lowest ethanol-to-acetic acid extraction ratio was obtained using TOPO. In a single-stage batch extraction, 97.0 % and 92.4 % of acetic acid could be extracted using TAPO and TOPO when the ratio of organic-to-aqueous phases is 4:1 respectively. A higher solvent-to-feed ratio resulted in an increase in the ethanol-to-acetic acid ratio, which decreased both acetic acid purity and acetic acid extraction yield.

  1. Acetic Acid Bacteria and the Production and Quality of Wine Vinegar

    Directory of Open Access Journals (Sweden)

    Albert Mas

    2014-01-01

    Full Text Available The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either “fast” or “traditional”, the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties.

  2. Acetic Acid Formation by Selective Aerobic Oxidation of Aqueous Ethanol over Heterogeneous Ruthenium Catalysts

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Hanning, Christopher William

    2012-01-01

    Heterogeneous catalyst systems comprising ruthenium hydroxide supported on different carrier materials, titania, alumina, ceria, and spinel (MgAl2O4), were applied in selective aerobic oxidation ethanol to form acetic acid, an important bulk chemical and food ingredient. The catalysts were...... of catalysts, oxidant pressure, reaction temperature, and substrate concentration were investigated. Quantitative yield of acetic acid was obtained with 1.2 wt % Ru(OH)x/CeO2 under optimized conditions (150 °C, 10 bar O2, 12 h of reaction time, 0.23 mol % Ru to substrate)....

  3. Acetic acid bacteria and the production and quality of wine vinegar.

    Science.gov (United States)

    Mas, Albert; Torija, María Jesús; García-Parrilla, María del Carmen; Troncoso, Ana María

    2014-01-01

    The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either "fast" or "traditional"), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties.

  4. Reaction Kinetics Between Acetic Acid and Ag2+

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The application of the salt-free reagents in the spent fuel reprocessing process has been investigated so much in the last years. Preferable result was obtained in the application of acetohydroxamic acid in the

  5. Preparation of Peracetic Acid from Acetic Acid and Hydrogen Peroxide: Experimentation and Modeling

    Institute of Scientific and Technical Information of China (English)

    赵雪冰; 张婷; 周玉杰; 刘德华

    2008-01-01

    Based on the kinetic equations and equilibrium constants, some mathematic models were developed for calculating peracetic acid (PAA) concentration, equilibrium conversion rate of hydrogen peroxide, etc. The effects of several parameters on PAA synthesis were investigated by experimentation and modeling. The equilibrium constants determined from the forward and reverse rate constants at 293, 303,313 and 323 K were 2.91, 2.81, 2.72 and 2.63, respectively. The models could predict the values of equilibrium concentration of PAA with average relative deviation of less than 10%. Both of the experimental and model-calculated results demonstrated that temperature and catalyst loading were the most important factors affecting the rate of PAA synthesis, but high temperature led to the decrease of equilibrium concentration of PAA. According to the model, the reaction could achieve equilibrium within 24 h when operated at 303 K with 1%~1.5%(ω) sulfuric acid as catalyst. Additionally, when using anhydrous acetic acid and 30% hydrogen peroxide to prepare PAA, the volumetric ratio of the two solutions should be in the range of 1.2~1.5 in order to obtain the highest equilibrium concentration of PAA. This study can serve as a step towards the further optimization of PAA synthesis and some other related investigations.

  6. Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal

    Directory of Open Access Journals (Sweden)

    Y. Tan

    2012-01-01

    Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 μM–10 mM was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

  7. Biosynthesis of biphenyls and benzophenones--evolution of benzoic acid-specific type III polyketide synthases in plants.

    Science.gov (United States)

    Beerhues, Ludger; Liu, Benye

    2009-01-01

    Type III polyketide synthases (PKSs) generate a diverse array of secondary metabolites by varying the starter substrate, the number of condensation reactions, and the mechanism of ring closure. Among the starter substrates used, benzoyl-CoA is a rare starter molecule. Biphenyl synthase (BIS) and benzophenone synthase (BPS) catalyze the formation of identical linear tetraketide intermediates from benzoyl-CoA and three molecules of malonyl-CoA but use alternative intramolecular cyclization reactions to form 3,5-dihydroxybiphenyl and 2,4,6-trihydroxybenzophenone, respectively. In a phylogenetic tree, BIS and BPS group together closely, indicating that they arise from a relatively recent functional diversification of a common ancestral gene. The functionally diverse PKSs, which include BIS and BPS, and the ubiquitously distributed chalcone synthases (CHSs) form separate clusters, which originate from a gene duplication event prior to the speciation of the angiosperms. BIS is the key enzyme of biphenyl metabolism. Biphenyls and the related dibenzofurans are the phytoalexins of the Maloideae. This subfamily of the Rosaceae includes a number of economically important fruit trees, such as apple and pear. When incubated with ortho-hydroxybenzoyl (salicoyl)-CoA, BIS catalyzes a single decarboxylative condensation with malonyl-CoA to form 4-hydroxycoumarin. A well-known anticoagulant derivative of this enzymatic product is dicoumarol. Elicitor-treated cell cultures of Sorbus aucuparia also formed 4-hydroxycoumarin when fed with the N-acetylcysteamine thioester of salicylic acid (salicoyl-NAC). BPS is the key enzyme of benzophenone metabolism. Polyprenylated benzophenone derivatives with bridged polycyclic skeletons are widely distributed in the Clusiaceae (Guttiferae). Xanthones are regioselectively cyclized benzophenone derivatives. BPS was converted into a functional phenylpyrone synthase (PPS) by a single amino acid substitution in the initiation/elongation cavity. The

  8. Acetic acid production from marine algae. Progress report No. 3, January 1, 1978--March 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, J.E.; Wise, D.L.

    1978-06-01

    The program for acetic acid production from marine algae has made significant progress in the current quarter. Some of the significant developments during this period are: (1) conversion of the available reducing equivalents in Chondrus crispus to organic acids has been carried to better than 80% completion; (2) thermophilic fermentations produce higher ratios of acetic acid to total acid than is the case for mesophilic fermentations (80% vs. 50%); (3) a membrane extraction process for removing organic acid products has been developed which has potential for commercial use; (4) a large scale fermentation was shown to convert over 50% of the available carbon in five days; (5) a reducing equivalents balance on the large scale fermentation was closed to with 96% of theoretical.

  9. Sphingolipid biosynthesis upregulation by TOR complex 2-Ypk1 signaling during yeast adaptive response to acetic acid stress.

    Science.gov (United States)

    Guerreiro, Joana F; Muir, Alexander; Ramachandran, Subramaniam; Thorner, Jeremy; Sá-Correia, Isabel

    2016-12-01

    Acetic acid-induced inhibition of yeast growth and metabolism limits the productivity of industrial fermentation processes, especially when lignocellulosic hydrolysates are used as feedstock in industrial biotechnology. Tolerance to acetic acid of food spoilage yeasts is also a problem in the preservation of acidic foods and beverages. Thus understanding the molecular mechanisms underlying adaptation and tolerance to acetic acid stress is increasingly important in industrial biotechnology and the food industry. Prior genetic screens for Saccharomyces cerevisiae mutants with increased sensitivity to acetic acid identified loss-of-function mutations in the YPK1 gene, which encodes a protein kinase activated by the target of rapamycin (TOR) complex 2 (TORC2). We show in the present study by several independent criteria that TORC2-Ypk1 signaling is stimulated in response to acetic acid stress. Moreover, we demonstrate that TORC2-mediated Ypk1 phosphorylation and activation is necessary for acetic acid tolerance, and occurs independently of Hrk1, a protein kinase previously implicated in the cellular response to acetic acid. In addition, we show that TORC2-Ypk1-mediated activation of l-serine:palmitoyl-CoA acyltransferase, the enzyme complex that catalyzes the first committed step of sphingolipid biosynthesis, is required for acetic acid tolerance. Furthermore, analysis of the sphingolipid pathway using inhibitors and mutants indicates that it is production of certain complex sphingolipids that contributes to conferring acetic acid tolerance. Consistent with that conclusion, promoting sphingolipid synthesis by adding exogenous long-chain base precursor phytosphingosine to the growth medium enhanced acetic acid tolerance. Thus appropriate modulation of the TORC2-Ypk1-sphingolipid axis in industrial yeast strains may have utility in improving fermentations of acetic acid-containing feedstocks.

  10. Culture strategies for lipid production using acetic acid as sole carbon source by Rhodosporidium toruloides.

    Science.gov (United States)

    Huang, Xiang-Feng; Liu, Jia-Nan; Lu, Li-Jun; Peng, Kai-Ming; Yang, Gao-Xiang; Liu, Jia

    2016-04-01

    Rhodosporidium toruloides AS 2.1389 was tested using different concentrations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20 g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions. At acetic acid concentrations as high as 20 g/L and the optimal carbon-to-nitrogen ratio (C/N) of 200 in a batch culture, the highest biomass production was 4.35 g/L, with a lipid content of 48.2%. At acetic acid concentrations as low as 4 g/L, a sequencing batch culture (SBC) with a C/N of 100 increased biomass production to 4.21 g/L, with a lipid content of 38.6%. These results provide usable culture strategies for lipid production by R. toruloides AS 2.1389 when using diverse waste-derived volatile fatty acids.

  11. Monolaurin and acetic acid inactivation of Listeria monocytogenes attached to stainless steel.

    Science.gov (United States)

    Oh, D H; Marshall, D L

    1996-03-01

    Individual and combined antimicrobial effects of monolaurin and acetic acid on Listeria monocytogenes planktonic cells or stainless-steel-adherent cells were determined in order to evaluate cell viability during a 25-min exposure period at 25 degrees C. A 10(7)-colony-forming units (CFU)/ml population of planktonic cells was completely inactivated by the synergistic combination of 1% acetic acid with 50 or 100 microg/ml of monolaurin within 25 or 20 min, respectively. Either compound alone caused partial but incomplete inactivation within the same time periods. A population of 10(5) CFU/cm2 of 1-day adherent cells on stainless steel was completely inactivated within 25 min, but with the highest concentrations of the combined chemicals, i.e., 1% acetic acid and 100 microg/ml of monolaurin. The combined chemical treatment again synergistically produced greater inhibition. A 10(6)-CFU/cm2 population of 7-day adherent cells was not completely inactivated within 25 min of exposure, although counts did decline. The results demonstrate increased resistance of attached L. monocytogenes to acetic acid and monolaurin and show that resistance increased with culture age. Combinations of organic acids and monolaurin might be considered as sanitizers of food contact surfaces, but activities of such combinations are likely to be less than other commonly used sanitizers.

  12. Luminescence and Electronic Spectral Studies of Some Synthesized Lanthanide Complexes Using Benzoic Acid Derivative and o-Phenanthroline.

    Science.gov (United States)

    Wankar, Sneha; Limaye, S N

    2015-07-01

    Lanthanide complexes of p-nitrobenzoic acid(p-NBA) and o-phenanthroline(o-phen) namely [Ln2(Phen)2(p-NBA)3(NO3)2].2H2O where, Ln = Sm(III),Tb(III),Dy(III) and [Eu2(Phen)2(p-NBA)3].4H2O were synthesized and further characterized by Elemental analysis, UV spectroscopy, IR spectroscopy, (1)HNMR spectroscopy. Luminescence measurements were performed on all compounds in ethanolic solution. These complexes have showed narrow emission indicating that the organic ligands are better energy absorber and capable of transferring energy to the Ln (III) ion. Furthermore, we reported electronic spectral studies on [Eu2 (Phen)2 (p-NBA)3].4H2O in order to calculate following parameters, viz: Oscillator strength (f), Judd-Ofelt parameters Ωλ (λ = 2,4,6) and Radiative parameters. [Eu2 (o-Phen)2 (p-NBA)3].4H2O showed the strongest emission at 613 nm corresponds to (5)D0→(7)F2 hypersensitive transition, this emission is very sensitive to the environment. However, the larger value of Ω2 supports the presence of the hypersensitive transition (5)D0→(7)F2 which strictly depends on the nature of ligand. All electronic spectral parameters were calculated systemically.

  13. Acetic Acid, the active component of vinegar, is an effective tuberculocidal disinfectant.

    Science.gov (United States)

    Cortesia, Claudia; Vilchèze, Catherine; Bernut, Audrey; Contreras, Whendy; Gómez, Keyla; de Waard, Jacobus; Jacobs, William R; Kremer, Laurent; Takiff, Howard

    2014-02-25

    Effective and economical mycobactericidal disinfectants are needed to kill both Mycobacterium tuberculosis and non-M. tuberculosis mycobacteria. We found that acetic acid (vinegar) efficiently kills M. tuberculosis after 30 min of exposure to a 6% acetic acid solution. The activity is not due to pH alone, and propionic acid also appears to be bactericidal. M. bolletii and M. massiliense nontuberculous mycobacteria were more resistant, although a 30-min exposure to 10% acetic acid resulted in at least a 6-log10 reduction of viable bacteria. Acetic acid (vinegar) is an effective mycobactericidal disinfectant that should also be active against most other bacteria. These findings are consistent with and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids. IMPORTANCE Mycobacteria are best known for causing tuberculosis and leprosy, but infections with nontuberculous mycobacteria are an increasing problem after surgical or cosmetic procedures or in the lungs of cystic fibrosis and immunosuppressed patients. Killing mycobacteria is important because Mycobacterium tuberculosis strains can be multidrug resistant and therefore potentially fatal biohazards, and environmental mycobacteria must be thoroughly eliminated from surgical implements and respiratory equipment. Currently used mycobactericidal disinfectants can be toxic, unstable, and expensive. We fortuitously found that acetic acid kills mycobacteria and then showed that it is an effective mycobactericidal agent, even against the very resistant, clinically important Mycobacterium abscessus complex. Vinegar has been used for thousands of years as a common disinfectant, and if it can kill mycobacteria, the most disinfectant-resistant bacteria, it may prove to be a broadly effective, economical biocide with potential usefulness in health care settings and laboratories, especially in resource-poor countries.

  14. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells.

    Science.gov (United States)

    Maruta, Hitomi; Yoshimura, Yukihiro; Araki, Aya; Kimoto, Masumi; Takahashi, Yoshitaka; Yamashita, Hiromi

    2016-01-01

    Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin.

  15. Neutral losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide via intramolecular rearrangement in electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Chai, Yunfeng; Gao, Guanwei; Shen, Shanshan; Liu, Xin; Lu, Chengyin

    2017-02-15

    Electrospray ionization (ESI) tandem mass spectrometry can be applied to determine structural information about organic compounds. The [M + Na](+) ion is one of the major precursor ions in ESI mass spectrometry, but its fragmentation mechanism study is still insufficient. This study reveals the interesting fragmentation reactions of the [M + Na](+) ions of methoxyfenozide and tebufenozide. The fragmentations of the [M + Na](+) , [M + Li](+) , and [M + H](+) ions of methoxyfenozide and tebufenozide were studied using a hybrid quadrupole-orbitrap mass spectrometer and an ion trap mass spectrometer. A hydrogen/deuterium (H/D)-exchange experiment in the amide group of methoxyfenozide allowed for the confirmation of the fragmentation mechanism. Density functional theory (DFT) calculations were performed for a further understanding of the fragmentation mechanism of the [M + Na](+) ion of methoxyfenozide. Neutral losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide were observed as the major fragmentation pathways. In contrast, similar fragmentations were not observed or minor pathways in the fragmentation of the [M + Li](+) and [M + H](+) ions of methoxyfenozide and tebufenozide. In addition, a minor product ion resulting from loss of NaOH was identified, which was the first reported example in the fragmentation of sodiated compounds in mass spectrometry. Losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na](+) ions of methoxyfenozide and tebufenozide are proposed to be formed through an intramolecular rearrangement reaction, which is supported by DFT calculations. An H/D-exchange experiment confirms that the carboxyl hydrogen of benzoic acid and the hydrogen of NaOH exclusively derive from the amide hydrogen of the precursor ion. This study enriches our knowledge on the Na(+) -induced fragmentation reactions. Copyright © 2016 John Wiley & Sons, Ltd

  16. Soil washing of chromium- and cadmium-contaminated sludge using acids and ethylenediaminetetra acetic acid chelating agent.

    Science.gov (United States)

    Gitipour, Saeid; Ahmadi, Soheil; Madadian, Edris; Ardestani, Mojtaba

    2016-01-01

    In this research, the effect of soil washing in the removal of chromium- and cadmium-contaminated sludge samples collected from Pond 2 of the Tehran Oil Refinery was investigated. These metals are considered as hazardous substances for human health and the environment. The carcinogenicity of chromate dust has been established for a long time. Cadmium is also a potential environmental toxicant. This study was carried out by collecting sludge samples from different locations in Pond 2. Soil washing was conducted to treat the samples. Chemical agents, such as acetic acid, ethylenediaminetetra acetic acid (EDTA) and hydrochloric acid, were used as washing solutions to remove chromium and cadmium from sludge samples. The results of this study indicated that the highest removal efficiencies from the sludge samples were achieved using a 0.3 M HCl solution with 82.69% and 74.47% for chromium and cadmium, respectively. EDTA (0.1 M) in the best condition extracted 66.81% of cadmium and 72.52% of chromium from the sludges. The lowest efficiency values for the samples, however, were achieved using 3 M acetic acid with 41.7% and 46.96% removals for cadmium and chromium, respectively. The analysis of washed sludge indicated that the heavy metals removal decreased in the order of 3 M acetic acid acid appears to offer a greater potential as a washing agent in remediating the sludge samples.

  17. The influence of surface oxygen and hydroxyl groups on the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate on pure Pd(1 0 0): A DFT study

    Science.gov (United States)

    Huang, Yanping; Dong, Xiuqin; Yu, Yingzhe; Zhang, Minhua

    2016-12-01

    On the basis of a Langmuir-Hinshelwood-type mechanism, the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate (VAH) on pure Pd(1 0 0) with surface oxygen atoms (Os) and hydroxyl groups (OHs) was studied with density functional theory (DFT) method. Our calculation results show that both Os and OHs can consistently reduce the activation energies of dehydrogenation of ethylene, acetic acid and VAH to some degree with only one exception that OHs somehow increase the activation energy of VAH. Based on Langmuir-Hinshelwood mechanism, the three dehydrogenation reactions in presence of surface Os and OHs are almost consistently favored, compared with the corresponding processes on clean Pd(1 0 0) surfaces, and thus a Langmuir-Hinshelwood-type mechanism may not be excluded beforehand when investigating the microscopic performance of the oxygen-assisted vinyl acetate synthesis on Pd(1 0 0) catalysts.

  18. CO2-enhanced extraction of acetic acid from fermented wastewater

    NARCIS (Netherlands)

    Reyhanitash, Ehsan; Zaalberg, B.; IJmker, H.M.; Kersten, Sascha R.A.; Schuur, Boelo

    2015-01-01

    The industrial process of recovering fermentation-based volatile fatty acids (VFAs) utilizes H2SO4 to acidify the fermentation broth containing VFA-salts [e.g. Ca(CH3COO)2] to enable formation of molecular VFAs. Molecular VFAs are then recovered by liquid–liquid extraction. However, acidification

  19. CO2-enhanced extraction of acetic acid from fermented wastewater

    NARCIS (Netherlands)

    Reyhanitash, E.; Zaalberg, B.; IJmker, H.M.; Kersten, S.R.A.; Schuur, B.

    2015-01-01

    The industrial process of recovering fermentation-based volatile fatty acids (VFAs) utilizes H2SO4 to acidify the fermentation broth containing VFA-salts [e.g. Ca(CH3COO)2] to enable formation of molecular VFAs. Molecular VFAs are then recovered by liquid–liquid extraction. However, acidification wi

  20. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    Science.gov (United States)

    Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large