Gaseous phase heat capacity of benzoic acid

NARCIS (Netherlands)

Santos, L.M.N.B.F.; Alves da Rocha, M.A.; Gomes, L.R.; Schröder, B.; Coutinho, J.A.P.

2010-01-01

The gaseous phase heat capacity of benzoic acid (BA) was proven using the experimental technique called the "in vacuum sublimation/vaporization Calvet microcalorimetry drop method". To overcome known experimental shortfalls, the gaseous phase heat capacity of BA monomer was estimated by ab initio

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

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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

Energetic and metabolic transient response of Saccharomyces cerevisiae to benzoic acid.

Science.gov (United States)

Kresnowati, M T A P; van Winden, W A; van Gulik, W M; Heijnen, J J

2008-11-01

Saccharomyces cerevisiae is known to be able to adapt to the presence of the commonly used food preservative benzoic acid with a large energy expenditure. Some mechanisms for the adaptation process have been suggested, but its quantitative energetic and metabolic aspects have rarely been discussed. This study discusses use of the stimulus response approach to quantitatively study the energetic and metabolic aspects of the transient adaptation of S. cerevisiae to a shift in benzoic acid concentration, from 0 to 0.8 mM. The information obtained also serves as the basis for further utilization of benzoic acid as a tool for targeted perturbation of the energy system, which is important in studying the kinetics and regulation of central carbon metabolism in S. cerevisiae. Using this experimental set-up, we found significant fast-transient (< 3000 s) increases in O(2) consumption and CO(2) production rates, of approximately 50%, which reflect a high energy requirement for the adaptation process. We also found that with a longer exposure time to benzoic acid, S. cerevisiae decreases the cell membrane permeability for this weak acid by a factor of 10 and decreases the cell size to approximately 80% of the initial value. The intracellular metabolite profile in the new steady-state indicates increases in the glycolytic and tricarboxylic acid cycle fluxes, which are in agreement with the observed increases in specific glucose and O(2) uptake rates.

Hydrogen-bonded co-crystal structure of benzoic acid and zwitterionic l-proline

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Aaron M. Chesna

2017-03-01

Full Text Available The title compound [systematic name: benzoic acid–pyrrolidin-1-ium-2-carboxylate (1/1], C7H6O2·C5H9NO2, is an example of the application of non-centrosymmetric co-crystallization for the growth of a crystal containing a typically centrosymmetric component in a chiral space group. It co-crystallizes in the space group P212121 and contains benzoic acid and l-proline in equal proportions. The crystal structure exhibits chains of l-proline zwitterions capped by benzoic acid molecules which form a C(5[R33(11] hydrogen-bonded network along [100]. The crystal structure is examined and compared to that of a similar co-crystal containing l-proline zwitterions and 4-aminobenzoic acid.

Comparison of the effect of benzoic acid addition on the fermentation process quality with untreated silages

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Petr Doležal

2004-01-01

Full Text Available The influence of benzoic acid and formic acid (positive control of ensilaged maize and pressed sugar beet pulp on quality fermentation processes was studied in a laboratory experiment. The effect of additive on the quality of fermentation process during maize ensiling was studied in a first model experiment. Preservatives such as formic acid and benzoic acid were added to ensiled maize at the concentration of 1L/t and 1 kg/t, respectively. When benzoic acid was used as a preservative, the pH and the N-NH3/ N total ratio decreased statistically (PSugar beet pulp silages with benzoic acid or formic acid after 32 days of storage had a better sensuous evaluation than the control silage. The most intensive decrease of pH value was observed after formic acid addition as compared with control silage. The statistically significantly (P<0.05 highest lactic acid content (49.64 ± 0.28 as well as the highest ratio of LA/VFA were found in the sugar beet pulp silage with benzoic acid. Lactic acid constituted the highest percentage (P<0.05 of all fermentation acids in the silage with benzoic acid additive (65.12 ± 0.80. Undesirable butyric acid (BA was not found in any variant of silages. The positive correlation between the titration acidity and acids sum in dry matter of silage conserved with formic acid was found. The additive of organic acids reduced significantly TA and fermentation acids content. Between the pH value and lactic acid content, no correlation was found.

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)

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

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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.

Ion-exclusion chromatography with conductimetric detection of aliphatic carboxylic acids on a weakly acidic cation-exchange resin by elution with benzoic acid-beta-cyclodextrin.

Science.gov (United States)

Tanaka, Kazuhiko; Mori, Masanobu; Xu, Qun; Helaleh, Murad I H; Ikedo, Mikaru; Taoda, Hiroshi; Hu, Wenzhi; Hasebe, Kiyoshi; Fritz, James S; Haddad, Paul R

2003-05-16

In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression.

High Performance Liquid Chromatography Determination of Urinary Hippuric Acid and Benzoic Acid as Indices for Glue Sniffer Urine

OpenAIRE

Abdul Rahim Yacob; Mohamad Raizul Zinalibdin

2010-01-01

A simple method for the simultaneous determination of hippuric acid and benzoic acid in urine using reversed-phase high performance liquid chromatography was described. Chromatography was performed on a Nova-Pak C18 (3.9 x 150 mm) column with a mobile phase of mixed solution methanol: water: acetic acid (20:80:0.2) and UV detection at 254 nm. The calibration curve was linear within concentration range at 0.125 to 6.0 mg/ml of hippuric acid and benzoic acid. The recovery, ...

Estimated intake of benzoic and sorbic acids in Denmark

DEFF Research Database (Denmark)

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

2010-01-01

limits, illegal use or declaration faults were found in about 3% of samples. From repeated investigations on fat-based foods (salads and dressings), marmalade and stewed fruit, it is concluded that the amounts used in industry have been relatively stable throughout the whole period, although limited data...... 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...

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.

Accurate prediction of the toxicity of benzoic acid compounds in mice via oral without using any computer codes

International Nuclear Information System (INIS)

Keshavarz, Mohammad Hossein; Gharagheizi, Farhad; Shokrolahi, Arash; Zakinejad, Sajjad

2012-01-01

Highlights: ► A novel method is introduced for desk calculation of toxicity of benzoic acid derivatives. ► There is no need to use QSAR and QSTR methods, which are based on computer codes. ► The predicted results of 58 compounds are more reliable than those predicted by QSTR method. ► The present method gives good predictions for further 324 benzoic acid compounds. - Abstract: Most of benzoic acid derivatives are toxic, which may cause serious public health and environmental problems. Two novel simple and reliable models are introduced for desk calculations of the toxicity of benzoic acid compounds in mice via oral LD 50 with more reliance on their answers as one could attach to the more complex outputs. They require only elemental composition and molecular fragments without using any computer codes. The first model is based on only the number of carbon and hydrogen atoms, which can be improved by several molecular fragments in the second model. For 57 benzoic compounds, where the computed results of quantitative structure–toxicity relationship (QSTR) were recently reported, the predicted results of two simple models of present method are more reliable than QSTR computations. The present simple method is also tested with further 324 benzoic acid compounds including complex molecular structures, which confirm good forecasting ability of the second model.

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

International Nuclear Information System (INIS)

Mandic, Zoran; Nigovic, Biljana; Simunic, Branimir

2004-01-01

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

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

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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.

Interactions of benzoic acid and phosphates with iron oxide colloids using chemical force titration.

Science.gov (United States)

Liang, Jana; Horton, J Hugh

2005-11-08

Colloidal iron oxides are an important component in soil systems and in water treatment processes. Humic-based organic compounds, containing both phenol and benzoate functional groups, are often present in these systems and compete strongly with phosphate species for binding sites on the iron oxide surfaces. Here, we examine the interaction of benzoate and phenolic groups with various iron oxide colloids using atomic force microscopy (AFM) chemical force titration measurements. Self-assembled monolayers (SAMs) of 4-(12-mercaptododecyloxy)benzoic acid and 4-(12-mercaptododecyloxy)phenol were used to prepare chemically modified Au-coated AFM tips, and these were used to probe the surface chemistry of a series of iron oxide colloids. The SAMs formed were also characterized using scanning tunneling microscopy, reflection-absorption infrared spectroscopy, and X-ray photoelectron spectroscopy. The surface pK(a) of 4-(12- mercaptododecyloxy)benzoic acid has been determined to be 4.0 +/- 0.5, and the interaction between the tip and the sample coated with a SAM of this species is dominated by hydrogen bonding. The chemical force titraton profile for an AFM probe coated with 4-(12- mercaptododecyloxy)benzoic acid and a bare iron oxide colloid demonstrates that the benzoic acid function group interacts with all three types of iron oxide sites present on the colloid surface over a wide pH range. Similar experiments were carried out on colloids precipitated in the presence of phosphoric, gallic, and tannic acids. The results are discussed in the context of the competitive binding interactions of solution species present in soils or in water treatment processes.

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

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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.

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....

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

The fragment ion C13H9O2 m/z 197 in the mass spectra of 2-(2'-R-phenyl)benzoic acids

International Nuclear Information System (INIS)

Gills, R.G.; Porter, Q.N.

1990-01-01

In the electron impact mass spectrum of 2-( ' -R-phenyl)benzoic acids where R = H, NO 2 , OCH 3 , COOH, or Br, and abundant fragment ion m/z 197 is formed by an ipso substitution in which R is expelled as a radical. The structure of the ion m/z 197 has been shown by collision-activated dissociation to be identical with that of the protonated molecule formed by methane chemical ionization of 6H-dibenzo[b,d]pyran-6-one. 11 refs., 1 fig., ills

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

OpenAIRE

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

Crystal structures of three co-crystals of 1,2-bis-(pyridin-4-yl)ethane with 4-alk-oxy-benzoic acids: 4-eth-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), 4-n-propoxybenzoic acid-1,2-bis(pyridin-4-yl)ethane (2/1) and 4-n-but-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1).

Science.gov (United States)

Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

2015-11-01

The crystal structures of three hydrogen-bonded co-crystals of 4-alk-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), namely, 2C9H10O3·C12H12N2, (I), 2C10H12O3·C12H12N2, (II), and 2C11H14O3·C12H12N2, (III), have been determined at 93, 290 and 93 K, respectively. In (I), the asymmetric unit consists of one 4-eth-oxy-benzoic acid mol-ecule and one half-mol-ecule of 1,2-bis-(pyridin-4-yl)ethane, which lies on an inversion centre. In (II) and (III), the asymmetric units each comprise two crystallographically independent 4-alk-oxy-benzoic acid mol-ecules and one 1,2-bis-(pyridin-4-yl)ethane mol-ecule. In each crystal, the two components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1unit of the acid and the base. Similar to the structure of 2:1 unit of (I), the units of (II) and (III) adopt nearly pseudo-inversion symmetry. The 2:1 units of (I), (II) and (III) are linked via C-H⋯O hydrogen bonds, forming tape structures.

Luminescence enhancement of uranyl ion by benzoic acid in acetonitrile

International Nuclear Information System (INIS)

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

2014-01-01

Uranyl ion is known for its characteristic green luminescence and therefore luminescence spectroscopy is a suitable technique for characterizing different uranyl species. In aqueous medium, luminescence of uranyl ion is generally weak due to its quenching by water molecules and therefore in order to enhance the luminescence of uranyl ion in aqueous medium, luminescence enhancing reagents such as H 3 PO 4 , H 2 SO 4 , HCIO 4 have been widely used. The other method to enhance the uranyl luminescence is by ligand sensitized luminescence, a method well established for lanthanides. In this work, luminescence of uranyl ion is found to be enhanced by benzoic acid in acetonitrile medium. In aqueous medium benzoic acid does not enhance the uranyl luminescence although it forms 1:1 and 1:2 complexes with uranyl ion. Luminescence spectra of uranyl benzoate revealed that enhancement is due to sensitization of uranyl luminescence by benzoate ions. UV-Vis spectroscopy has been utilized to characterize the specie formed in the in acetonitrile medium. UV-Vis spectroscopy along with luminescence spectra revealed that the specie to be tribenzoate complex of uranyl (UO 2 (C 6 H 5 COO) 3 ) - having D 3 h symmetry. (author)

Direct quantitation of the preservatives benzoic and sorbic acid in processed foods using derivative spectrophotometry combined with micro dialysis.

Science.gov (United States)

Fujiyoshi, Tomoharu; Ikami, Takahito; Kikukawa, Koji; Kobayashi, Masato; Takai, Rina; Kozaki, Daisuke; Yamamoto, Atsushi

2018-02-01

The preservatives benzoic acid and sorbic acid are generally quantified with separation techniques, such as HPLC or GC. Here we describe a new method for determining these compounds in processed food samples based on a narrowness of the UV-visible spectral band width with derivative processing. It permits more selective identification and determination of target analytes in matrices. After a sample is purified by micro dialysis, UV spectra of sample solutions were measured and fourth order derivatives of the spectrum were calculated. The amplitude between the maximum and minimum values in a high-order derivative spectrum was used for the determination of benzoic acid and sorbic acid. Benzoic acid and sorbic acid levels in several commercially available processed foods were measured by HPLC and the proposed spectrometry method. The levels obtained by the two methods were highly correlated (r 2 >0.97) for both preservatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Docking of oxalyl aryl amino benzoic acid derivatives into PTP1B

Science.gov (United States)

Verma, Neelam; Mittal, Minakshi; Verma, Raman kumar

2008-01-01

Protein Tyrosine Phosphatases (PTPs) that function as negative regulators of the insulin signaling cascade have been identified as novel targets for the therapeutic enhancement of insulin action in insulin resistant disease states. Reducing Protein Tyrosine Phosphatase1B (PTP1B) abundance not only enhances insulin sensitivity and improves glucose metabolism but also protects against obesity induced by high fat feeding. PTP1B inhibitors such as Formylchromone derivatives, 1, 2-Naphthoquinone derivatives and Oxalyl aryl amino benzoic derivatives may eventually find an important clinical role as insulin sensitizers in the management of Type-II Diabetes and metabolic syndrome. We have carried out docking of modified oxalyl aryl amino benzoic acid derivatives into three dimensional structure of PTP1B using BioMed CAChe 6.1. These compounds exhibit good selectivity for PTP1B over most of phosphatases in selectivity panel such as SHP-2, LAR, CD45 and TCPTP found in literature. This series of compounds identified the amino acid residues such as Gly220 and Arg221 are important for achieving specificity via H-bonding interactions. Lipophilic side chain of methionine in modified oxalyl aryl amino benzoic acid derivative [1b (a2, b2, c1, d)] lies in closer vicinity of hydrophobic region of protein consisted of Meth258 and Phe52 in comparison to active ligand. Docking Score in [1b (a2, b2, c1, d)] is -131.740Kcal/mol much better than active ligand score -98.584Kcal/mol. This information can be exploited to design PTP1B specific inhibitors. PMID:19238234

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

Science.gov (United States)

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. PMID:16346592

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

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

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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.

Validated HPLC method for identification and quantification of p-hydroxy benzoic acid and agnuside in Vitex negundo and Vitex trifolia

Directory of Open Access Journals (Sweden)

Sonal Shah

2013-12-01

Full Text Available A high performance liquid chromatography coupled with photodiode array detection method was developed for the identification and quantification of p-hydroxy benzoic acid and agnuside in the extracts of Vitex negundo and Vitex trifolia. The separation was achieved using acetonitrile and O-phosphoric acid–water (0.5%, v/v as the mobile phase in an isocratic elution mode. Mean retention times of standard p-hydroxy benzoic acid and agnuside were 6.14 and 11.90 min respectively. The developed method was validated as per the ICH guidelines for limit of detection, limit of quantification, linearity, accuracy and precision. Good linearity (r2≥0.999 was observed for both the compounds in wide concentration range. Relative standard deviation values for intra-day and inter-day precision studies were less than 2%. The analytical recoveries of p-hydroxy benzoic acid and agnuside by the developed HPLC method were 93.07% and 106.11% respectively. Two compounds were identified and quantified in leaves and bar extracts of V. negundo and V. trifolia using the developed HPLC method. Keywords: Vitex negundo, Vitex trifolia, HPLC-PDA, p-Hydroxy benzoic acid, Agnuside

Effects of benzoic acid and cadmium toxicity on wheat seedlings

Directory of Open Access Journals (Sweden)

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.

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.

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,

Inhibition of denitrification and N2O emission by urine-derived benzoic and hippuric acid

NARCIS (Netherlands)

Groenigen, van J.W.; Palermo, V.; Kool, D.M.; Kuikman, P.J.

2006-01-01

Hippuric acid (HA) in cattle urine acts as a natural inhibitor of soil N2O emissions. As HA concentration varies with diet, we determined critical HA levels. We also tested the hypothesis that the inhibition occurs because the HA breakdown product benzoic acid (BA) inhibits denitrification rates.

Dietary Supplementation of Benzoic Acid and Essential Oil Compounds Affects Buffering Capacity of the Feeds, Performance of Turkey Poults and Their Antioxidant Status, pH in the Digestive Tract, Intestinal Microbiota and Morphology

Directory of Open Access Journals (Sweden)

I. Giannenas

2014-02-01

Full Text Available Three trials were conducted to evaluate the effect of supplementation of a basal diet with benzoic acid or thymol or a mixture of essential oil blends (MEO or a combination of benzoic acid with MEO (BMEO on growth performance of turkey poults. Control groups were fed a basal diet. In trial 1, benzoic acid was supplied at levels of 300 and 1,000 mg/kg. In trial 2, thymol or the MEO were supplied at levels of 30 mg/kg. In trial 3, the combination of benzoic acid with MEO was evaluated. Benzoic acid, MEO and BMEO improved performance, increased lactic acid bacteria populations and decreased coliform bacteria in the caeca. Thymol, MEO and BMEO improved antioxidant status of turkeys. Benzoic acid and BMEO reduced the buffering capacity compared to control feed and the pH values of the caecal content. Benzoic acid and EOs may be suggested as an effective alternative to AGP in turkeys.

Studies on 2-(toluene-4-sulfonylamino)-benzoic acid: structure spectroscopic properties

International Nuclear Information System (INIS)

Tarcan, E.; Atalay, Y.; Guenay, N.

2010-01-01

The molecular geometry, vibrational (IR) spectrum, vibrational frequencies and 1 H and 1 3C NMR chemical shifts were carried out of 2-(toluene-4-sulfonylamino)-benzoic acid with ab initio and density functional computations. On the basis of the comparison between calculated and experimental results assignments of fundamental vibrational modes are examined. The X-ray geometry, experimental frequencies and chemical shifts are compared with the results of our theoretical calculations

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

NARCIS (Netherlands)

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

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

Oxidation of benzoic acid by heat-activated persulfate: Effect of temperature on transformation pathway and product distribution.

Science.gov (United States)

Zrinyi, Nick; Pham, Anh Le-Tuan

2017-09-01

Heat activates persulfate (S 2 O 8 2- ) into sulfate radical (SO 4 - ), a powerful oxidant capable of transforming a wide variety of contaminants. Previous studies have shown that an increase in temperature accelerates the rates of persulfate activation and contaminant transformation. However, few studies have considered the effect of temperature on contaminant transformation pathway. The objective of this study was to determine how temperature (T = 22-70 °C) influences the activation of persulfate, the transformation of benzoic acid (i.e., a model compound), and the distribution of benzoic acid oxidation products. The time-concentration profiles of the products suggest that benzoic acid was transformed via decarboxylation and hydroxylation mechanisms, with the former becoming increasingly important at elevated temperatures. The pathway through which the products were further oxidized was also influenced by the temperature of persulfate activation. Our findings suggest that the role of temperature in the persulfate-based treatment systems is not limited only to controlling the rates of sulfate and hydroxyl radical generation. The ability of sulfate radical to initiate decarboxylation reactions and, more broadly, fragmentation reactions, as well as the effect of temperature on these transformation pathways could be important to the transformation of a number of organic contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

ON THE FORMATION OF BENZOIC ACID AND HIGHER-ORDER BENZENE CARBOXYLIC ACIDS IN INTERSTELLAR MODEL ICE GRAINS

Energy Technology Data Exchange (ETDEWEB)

McMurtry, Brandon M.; Saito, Sean E. J.; Turner, Andrew M.; Chakravarty, Harish K.; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

2016-11-10

With a binary ice mixture of benzene (C{sub 6}H{sub 6}) and carbon dioxide (CO{sub 2}) 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.

Liquid-liquid extraction systems of benzoic acid in water, heptane, methylbenzene or trichloroethylene as co-solvent

NARCIS (Netherlands)

Visscher, F.; Gaakeer, W.A.; Granados Mendoza, P.; Croon, de M.H.J.M.; Schaaf, van der J.; Schouten, J.C.

2011-01-01

Equilibrium data at (293 ± 2) K are presented for benzoic acid in water and three different organic phases (heptane, methylbenzene, and trichloroethylene). The monomeric partition constant, KPMON, and the dimerization constant, KD, for the organic phase were determined at 293 K. For the

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

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...

Optical modulation in nematic phase of halogen substituted hydrogen bonded liquid crystals

Science.gov (United States)

Vijayakumar, V. N.; Madhu Mohan, M. L. N.

2012-01-01

A series of halogen-substituted hydrogen-bonded liquid crystalline complexes have been designed and synthesised. A successful attempt has been made to form complementary hydrogen bonding between the dodecyloxy benzoic acid (12BAO) and halogen-substituted benzoic acids and the physical properties exhibited by the individual complexes are studied. The complexes obtained are analysed by polarising optical microscope (POM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and dielectric studies. The formation of complementary hydrogen bond is confirmed through FTIR spectra. An interesting feature of this series is the observation of a field-induced transition (FiT) in nematic phase. Another interesting phenomenon is the observation of a new smectic X phase (worm-like texture) in all the synthesised complexes. Dielectric relaxation studies in the smectic C phase of these hydrogen bonded complexes along with the Arrhenius and the Cole-Cole plots are discussed. Optical tilt angle in smectic C phase and the corresponding fitted data analysis concur with the Mean field theory prediction.

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.

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

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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.

Warm season precipitation signal in δ2 H values of wood lignin methoxyl groups from high elevation larch trees in Switzerland.

Science.gov (United States)

Riechelmann, Dana F C; Greule, Markus; Siegwolf, Rolf T W; Anhäuser, Tobias; Esper, Jan; Keppler, Frank

2017-10-15

In this study, we tested stable hydrogen isotope ratios of wood lignin methoxyl groups (δ 2 H methoxyl values) as a palaeoclimate proxy in dendrochronology. This is a quite new method in the field of dendrochronology and the sample preparation is much simpler than the methods used before to measure δ 2 H values from wood. We measured δ 2 H methoxyl values in high elevation larch trees (Larix decidua Mill.) from Simplon Valley (southern Switzerland). Thirty-seven larch trees were sampled and five individuals analysed for their δ 2 H methoxyl values at annual (1971-2009) and pentadal resolution (1746-2009). The δ 2 H methoxyl values were measured as CH 3 I released upon treatment of the dried wood samples with hydroiodic acid. 10-90 μL from the head-space were injected into the gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/HTC-IRMS) system. Testing the climate response of the δ 2 H methoxyl values, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation. The pentadally resolved δ 2 H methoxyl series do not show any significant correlation to climate parameters. Increased precipitation during June and July, which are on average warm and relatively dry months, results in higher δ 2 H values of the xylem water and, therefore, higher δ 2 H values in the lignin methoxyl groups. Therefore, we suggest that δ 2 H methoxyl values of high elevation larch trees might serve as a summer precipitation proxy. Copyright © 2017 John Wiley & Sons, Ltd.

Synthesis, structural characterization and quantum chemical studies of silicon-containing benzoic acid derivatives

Science.gov (United States)

Zaltariov, Mirela-Fernanda; Cojocaru, Corneliu; Shova, Sergiu; Sacarescu, Liviu; Cazacu, Maria

2016-09-01

The present paper is concerned with the synthesis and molecular structure investigation of two new benzoic acid derivatives having trimethylsilyl tails, 4-((trimethylsilyl)methoxy) and 4-(3-(trimethylsilyl)propoxy)benzoic acids. The structures of the novel compounds have been confirmed by X-ray crystallography, Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 13C NMR). The theoretical studies of molecules were conducted by using the quantum chemical methods, such as Density Functional Theory (DFT B3LYP/6-31 + G**), Hartree-Fock (HF/6-31 + G**) and semiempirical computations (PM3, PM6 and PM7). The optimized molecular geometries have been found to be in good agreement with experimental structures resulted from the X-ray diffraction. The maximum electronic absorption bands observed at 272-287 nm (UV-vis spectra) have been assigned to π → π* transitions, which were in reasonable agreement with the time dependent density functional theory (TD-DFT) calculations. The computed vibrational frequencies by DFT method were assigned and compared with the experimental FTIR spectra. The mapped electrostatic potentials revealed the reactive sites, which corroborated the observation of the dimer supramolecular structures formed in the crystals by hydrogen-bonding. The energies of frontier molecular orbitals (HOMO and LUMO), energy gap, dipole moment and molecular descriptors for the new compounds were calculated and discussed.

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

Radiation chemistry of salicylic and methyl substituted salicylic acids: Models for the radiation chemistry of pharmaceutical compounds

International Nuclear Information System (INIS)

Ayatollahi, Shakiba; Kalnina, Daina; Song, Weihua; Turks, Maris; Cooper, William J.

2013-01-01

Salicylic acid and its derivatives are components of many medications and moieties found in numerous pharmaceutical compounds. They have been used as models for various pharmaceutical compounds in pharmacological studies, for the treatment of pharmaceuticals and personal care products (PPCPs), and, reactions with natural organic matter (NOM). In this study, the radiation chemistry of benzoic acid, salicylic acid and four methyl substituted salicylic acids (MSA) is reported. The absolute bimolecular reaction rate constants for hydroxyl radical reaction with benzoic and salicylic acids as well as 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-salicylic acid were determined (5.86±0.54)×10 9 , (1.07±0.07)×10 10 , (7.48±0.17)×10 9 , (7.31±0.29)×10 9 , (5.47±0.25)×10 9 , (6.94±0.10)×10 9 (M −1 s −1 ), respectively. The hydrated electron reaction rate constants were measured (3.02±0.10)×10 9 , (8.98±0.27)×10 9 , (5.39±0.21)×10 9 , (4.33±0.17)×10 9 , (4.72±0.15)×10 9 , (1.42±0.02)×10 9 (M −1 s −1 ), respectively. The transient absorption spectra for the six model compounds were examined and their role as model compounds for the radiation chemistry of pharmaceuticals investigated. - Highlights: • Free radical chemistry of salicylic and 4 methyl salicylic acids is investigated. • The transient absorptions spectra for model compounds are measured. • Absolute bimolecular reaction rate constants for hydroxyl radical are determined. • Solvated electron reaction rate constants are calculated. • The use of salicylic acids as models for pharmaceuticals is explored

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.

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

Rh(III) -Catalyzed C-H Olefination of Benzoic Acids under Mild Conditions using Oxygen as the Sole Oxidant.

Science.gov (United States)

Jiang, Quandi; Zhu, Changlei; Zhao, Huaiqing; Su, Weiping

2016-02-04

Phthalide skeletons have been synthesized for the first time through a Rh(III) -catalyzed C-H olefination of benzoic acids under mild conditions using oxygen as the sole oxidant. Aromatic acids bearing a variety of functional groups could react with diverse alkenes to afford the desired cyclized lactones or uncyclized alkenylarenes in moderate-to-excellent yields. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Calibration of brachytherapy sources using ferrous sulphate-benzoic acid-xylenol orange dosimeter

International Nuclear Information System (INIS)

Madhvanath, U.; Kini, U.R.; Gupta, B.L.

1976-01-01

A solution containing 0.20 mM of ferrous ammonium sulphate, 5.0 mM benzoic acid and 0.20 mM xylenol orange in 0.05 N sulphuric acid was used for the calibration of 252 Cf, 137 Cs, 226 Ra and 60 Co needle sources. A known volume of this solution contained in a pyrex glass tube was irradiated with the source kept in a glass capillary at the centre of the solution. A few hours of irradiation were required for each needle and the absorbance of the solution was measured at 540 nm against the unirradiated solution. The accuracy of this method was found to be within a few percent and is particularly useful for 252 Cf sources as the neutron component of the source contributes significantly to the absorbance produced. (author)

THE INFLUENCE OF THE EXTRACTION TEMPERATURE ON THE RENDEMENT AND PECTIN METHOXYL CONTENTS OF WATERHYACINTH (Eichornia crassipes (Mart Solms

Directory of Open Access Journals (Sweden)

Ika Daniarsari

2010-06-01

Full Text Available The purpose of this research is to find out the influence of the extraction temperature on the rendement and pectin methoxyl contents of waterhyacinth with the applied temperatures ranged from 60, 70, 80, 90 and 100 °C.The stages of this research involve extraction, precipitation, washing and drying. The pectin produced was, then, identified by reacting it with water, ethanol 96 %, NaOH and spectrophotometer IR. Its product was, then, compared to the comparing pectin. To determine the methoxyl contents, the acid - base titration was used. The resulting data were analysed and tested using One Direction Anava with SPSS 10.0 program. From the quantitative used by this study, pectin was produced. This is shown by the gel-formation. The rendements produced with the extraction temperatures of 60, 70, 80, 90 and 100 °C were 0,428 %; 0,487 %; 0,629 %; 0,774 % and 0,958% respectively. While its methoxyl contents were 3,879 %; 3,993 %; 4,413 %; 3,573 % and 2,837 %. Based on the analysed data, it was found that the treatment with the extraction temperature gives a significant influence on the rendement and pectin methoxyl contents of waterhyacinth. Keywords: extraction, pectin, methoxyl contents

Halogeno-substituted 2-aminobenzoic acid derivatives for negative ion fragmentation studies of N-linked carbohydrates.

Science.gov (United States)

Harvey, David J

2005-01-01

Negative ion electrospray mass spectra of high-mannose N-linked glycans derivatised with 2-aminobenzoic acids and ionised from solutions containing ammonium hydroxide gave prominent [M-H](-) ions accompanied by weaker [M-2H](2-) ions. Fragmentation of both types of ions gave prominent singly charged glycosidic cleavage ions containing the derivatised reducing terminus and ions from the non-reducing terminus that appeared to be products of cross-ring cleavages. Differentiation of these two groups of ions was conveniently achieved in a single spectrum by use of chloro- or bromo-substituted benzoic acids in order to label ions containing the derivative with an atom with a distinctive isotope pattern. Fragmentation of the doubly charged ions gave more abundant fragments, both singly and doubly charged, than did fragmentation of the singly charged ions, but information of chain branching was masked by the appearance of prominent ions produced by internal cleavages. Copyright (c) 2005 John Wiley & Sons, Ltd.

Quantification of centimeter-scale spatial variation in PAH, glucose and benzoic acid mineralization and soil organic matter in road-side soil

Energy Technology Data Exchange (ETDEWEB)

Hybholt, Trine K.; Aamand, Jens [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Johnsen, Anders R., E-mail: arj@geus.dk [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

2011-05-15

The aim of the study was to determine centimeter-scale spatial variation in mineralization potential in diffusely polluted soil. To this end we employed a 96-well microplate method to measure the mineralization of {sup 14}C-labeled organic compounds in deep-well microplates and thereby compile mineralization curves for 348 soil samples of 0.2-cm{sup 3}. Centimeter-scale spatial variation in organic matter and the mineralization of glucose, benzoic acid, and PAHs (phenanthrene and pyrene) was determined for urban road-side soil sampled as arrays (7 x 11 cm) of 96 subsamples. The spatial variation in mineralization was visualized by means of 2-D contour maps and quantified by means of semivariograms. The geostatistical analysis showed that the easily degradable compounds (glucose and benzoic acid) exhibited little spatial variation in mineralization potential, whereas the mineralization was highly heterogeneous for the PAH compounds that require specialized degraders. The spatial heterogeneity should be taken into account when estimating natural attenuation rates. - Highlights: > Geostatistics were applied at the centimeter scale. > Glucose and benzoic acid mineralization showed little spatial variation. > PAH mineralization was highly variable at the sub-centimeter scale. > High spatial heterogeneity may be caused by low functional redundancy. - This study supports the hypothesis that specialized xenobiotic degraders may show high spatial heterogeneity in soil due to low functional redundancy.

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...

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...

Syntheses and structures of three heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid

International Nuclear Information System (INIS)

Fang, Wei-Hui; Yang, Guo-Yu

2014-01-01

Three lanthanide–transition-metal coordination polymers, namely, [Er 2 L 6 (H 2 O)][Cu 2 I 2 ] (1), [ErL 3 ][CuI] (2), and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ] (3) (HL=4-pyridin-3-yl-benzoic acid, H 2 BPDC=4,4′-biphenyldicarboxylic acid) have been made by reacting Ln 2 O 3 and CuI with HL at different temperatures under hydrothermal conditions. All the complexes are characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1–3 all construct from dimeric (Ln 2 ) and (Cu 2 ) units and exhibit two types of the structural features: 1 is a two-dimensional layer, 2–3 are three-dimensional frameworks. Interestingly, the in situ formation of the BPDC ligand is found in the structure of 3. The distinct architectures of these complexes indicated that the reaction temperature plays an important role in the formation of higher dimensional coordination polymers. - Graphical abstract: By hydrothermal reaction of lanthanide oxide, copper halide, and 4-pyridin-3-yl-benzoic ligand at different temperatures, a series of 1-D to 3-D 3d–4f coordination polymers, namely [ErL 3 (H 2 O) 2 ][CuI], [Er 2 L 6 (H 2 O)][Cu 2 I 2 ], [ErL 3 ][CuI], and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ], have been made, respectively. - Highlights: • Three novel heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid have been hydrothermally synthesized. • Mixed dinuclear motifs of (Ln 2 ) and (Cu 2 ) serve as secondary building units to generate 2-D layer and 3-D frameworks. • It is proved that higher temperature is apt to permit construction of high dimensional architectures

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.

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.

Synthesis, characterization and biological studies of 2-(4-nitro phenylaminocarbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

International Nuclear Information System (INIS)

Aqeel Ashraf, M.; Jamil Maah, M.; Yusuf, I.

2012-01-01

Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) salts of 2-(4-nitro phenylaminocarbonyl)benzoic acid were characterized by physical, analytical and spectroscopic studies and checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis (Gram +ve), Escherichia coli (Gram -ve), Pseudomonas aeuroginosa (Gram -ve) and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. The antimicrobial activities of the metal complexes - were found to be greater than those of 2-(4-nitro phenylaminocarbonyl)benzoic acid alone.

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.

Synthesis and stability of strongly acidic benzamide derivatives

DEFF Research Database (Denmark)

Diness, Frederik; Bjerrum, Niels J.; Begtrup, Mikael

2018-01-01

Reactivity studies of strong organic acids based on the replacement of one or both of the oxygens in benzoic acids with the trifluoromethanesulfonamide group are reported. Novel derivatives of these types of acids were synthesized in good yields. The generated N-triflylbenzamides were further...... functionalized through cross-coupling and nucleophilic aromatic substitution reactions. All compounds were stable in dilute aqueous solutions. Studies of stability under acidic and basic conditions are also reported....

Quantitative DFT modeling of product concentration in organometallic reactions: Cu-mediated pentafluoroethylation of benzoic acid chlorides as a case study.

Science.gov (United States)

Jover, Jesús

2017-11-08

DFT calculations are widely used for computing properties, reaction mechanisms and energy profiles in organometallic reactions. A qualitative agreement between the experimental and the calculated results seems to usually be enough to validate a computational methodology but recent advances in computation indicate that a nearly quantitative agreement should be possible if an appropriate DFT study is carried out. Final percent product concentrations, often reported as yields, are by far the most commonly reported properties in experimental metal-mediated synthesis studies but reported DFT studies have not focused on predicting absolute product amounts. The recently reported stoichiometric pentafluoroethylation of benzoic acid chlorides (R-C 6 H 4 COCl) with [(phen)Cu(PPh 3 )C 2 F 5 ] (phen = 1,10-phenanthroline, PPh 3 = triphenylphosphine) has been used as a case study to check whether the experimental product concentrations can be reproduced by any of the most popular DFT approaches with high enough accuracy. To this end, the Gibbs energy profile for the pentafluoroethylation of benzoic acid chloride has been computed using 14 different DFT methods. These computed Gibbs energy profiles have been employed to build kinetic models predicting the final product concentration in solution. The best results are obtained with the D3-dispersion corrected B3LYP functional, which has been successfully used afterwards to model the reaction outcomes of other simple (R = o-Me, p-Me, p-Cl, p-F, etc.) benzoic acid chlorides. The product concentrations of more complex reaction networks in which more than one position of the substrate may be activated by the copper catalyst (R = o-Br and p-I) are also predicted appropriately.

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

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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.

Cacao pod husks as a source of low-methoxyl, highly acetylated pectins able to gel in acidic media.

Science.gov (United States)

Vriesmann, Lúcia Cristina; de Oliveira Petkowicz, Carmen Lúcia

2017-08-01

Cacao pod husks, the main by-product from cocoa production, have been investigated for pectin isolation. In the present study, the rheological properties of two low-methoxyl (LM) pectins isolated from cacao pod husks using different extraction conditions were evaluated. One pectin was obtained from optimized conditions employing aqueous nitric acid as an extractant, and the other one was extracted with boiling water. Pectin gels (0.99% galacturonic acid equivalent, w/w) were prepared at pH 2.5-3.0 in the presence of 60% sucrose (w/w) and subjected to rheological analysis. Dynamic oscillatory experiments at 25°C indicated that better gels were obtained at the lowest pH (2.5). Steady shear measurements revealed a shear-thinning behavior. The apparent viscosities of the samples increased as pH decreased. Gelation with calcium ions was not observed for either of the highly acetylated LM pectins analyzed. The rheological analysis results showed that despite their high acetyl content, LM pectins extracted by different methods from cacao pod husks were able to form gels at low pH under reduced water activity, suggesting a possible application in acidic products. Copyright © 2017 Elsevier B.V. All rights reserved.

What climate information is recorded in stable isotope ratios of wood lignin methoxyl groups?

Science.gov (United States)

Greule, Markus; Keppler, Frank

2010-05-01

The stable isotope composition of the bioelements C, O, H and N in plant organic matter is known to be a very powerful for various environmental impacts. Particularly tree rings are suitable for this analysis because they exhibit a "climate archive" with a yearly or even biannual resolution. One of the most determined wood compounds is cellulose which amongst others is used to reconstruct the temperature due to measurement of stable hydrogen and oxygen isotopes. Therefore cellulose is converted into cellulose nitrate to eliminate the exchangeable hydroxyl hydrogen or equilibration methods are used. However, a general problem associated with the determination of the stable hydrogen values of marker compounds for the study of climate and environmental conditions is the isolation of the pure compound for analysis by isotope ratio mass spectrometry. Exploitation of components of wood as markers, in particular, has been restricted by the very labour intensive and time consuming preparation of samples (e.g. cellulose nitrate). An alternative way to record climate information from tree rings was recently proposed by Keppler et al. (2007) who measured the stable hydrogen values of methoxyl groups in wood. Lignin methoxyl groups are considered to be stable, i.e. the hydrogen atoms of the methoxyl moiety do not exchange with those of plant water during ongoing metabolic reactions in the plant. Thus the initial deuterium content of the methoxyl groups of lignin in woody tissue at formation is retained throughout the lifetime of the tree and in preserved tissue. The methoxyl content of lignin in wood is usually determined by the Zeisel method (Zeisel, 1885) - the reaction between methyl ethers and hydroiodic acid to form methyl iodide. Exploiting this reaction for the measurement of stable hydrogen values of lignin methoxyl groups ensures that during the entire analytical procedure the isotope signal is preserved since no isotopic exchange occurs between the methyl groups and

Synthesis of selectively 13C-labelled benzoic acid for nuclear magnetic resonance spectroscopic measurement of glycine conjugation activity

International Nuclear Information System (INIS)

Akira, Kazuki; Hasegawa, Hiroshi; Baba, Shigeo

1995-01-01

The synthesis of [4- 13 C]benzoic acid (BA) labelled in a single protonated carbon, for use as a probe to measure glycine conjugation activity by nuclear magnetic resonance (NMR) spectroscopy, has been reported. The labelled compound was prepared by a seven-step synthetic scheme on a relatively small scale using [2- 13 C] acetone as the source of label in overall yield of 16%. The usefulness of [4- 13 C]BA was demonstrated by the NMR spectroscopic monitoring of urinary excretion of [4- 13 C]hippuric acid in the rat administered with the labelled BA. (Author)

Benzoic Acid Derivatives with Trypanocidal Activity: Enzymatic Analysis and Molecular Docking Studies toward Trans-Sialidase

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Muhammad Kashif

2017-10-01

Full Text Available Chagas, or American trypanosomiasis, remains an important public health problem in developing countries. In the last decade, trans-sialidase has become a pharmacological target for new anti-Chagas drugs. In this work, the aims were to design and find a new series of benzoic acid derivatives as trans-sialidase (TS inhibitors and anti-trypanosomal agents. Three compounds (14, 18, and 19 sharing a para-aminobenzoic acid moiety showed more potent trypanocidal activity than the commercially available drugs nifurtimox and benznidazole in both strains: the lysis concentration of 50% of the population (LC50 was <0.15 µM on the NINOA strain, and LC50 < 0.22 µM on the INC-5 strain. Additionally, compound 18 showed a moderate inhibition (47% on the trans-sialidase enzyme and a binding model similar to DANA (pattern A.

Evidence of quantum correlations in the H/D-transfer dynamics in the hydrogen bonds in partially deuterated benzoic acid crystals

Science.gov (United States)

Takeda, Sadamu; Tsuzumitani, Akihiko; Chatzidimitriou-Dreismann, C. A.

1992-10-01

A precise investigation of spin—lattice relaxation rates for protons and deuterons of partially deuterated benzoic acid crystals showed a remarkable quenching of the transfer rate of an HD pair in hydrogen-bonded dimeric units of carboxyl groups with increasing concentration of D in the surrounding hydrogen bonds. A similar effect was also observed for partially deuterated crystals of acetylenedicarboxylic acid. This finding supports recent theoretical predictions of thermally activated protonic quantum correlation in condensed matter and proposes a new mechanism for the proton transfer in hydrogen bonds in condensed matter.

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

Science.gov (United States)

Gheibi, Nematollah; Taherkhani, Negar; Ahmadi, Abolfazl; Haghbeen, Kamahldin; Ilghari, Dariush

2015-02-01

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. 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. 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. 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) were comparable 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.

Crystal structures of a manganese(I and a rhenium(I complex of a bipyridine ligand with a non-coordinating benzoic acid moiety

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Sheri Lense

2018-05-01

Full Text Available The structures of two facially coordinated Group VII metal complexes are reported, namely: fac-bromido[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylmanganese(I tetrahydrofuran monosolvate, [MnBr(C17H12N2O2(CO3]·C4H8O, I, and fac-[2-(2,2′-bipyridin-6-ylbenzoic acid-κ2N,N′]tricarbonylchloridorhenium(I tetrahydrofuran monosolvate, [ReCl(C17H12N2O2(CO3]·C4H8O, II. In both complexes, the metal ion is coordinated by three carbonyl ligands, a halide ion, and a 2-(2,2′-bipyridin-6-ylbenzoic acid ligand, in a distorted octahedral geometry. In manganese complex I, the tetrahydrofuran (THF solvent molecule could not be refined due to disorder. The benzoic acid fragment is also disordered over two positions, such that the carboxylic acid group is either positioned near to the bromide ligand or to the axial carbonyl ligand. In the crystal of I, the complex molecules are linked by a pair of C—H...Br hydrogen bonds, forming inversion dimers that stack up the a-axis direction. In the rhenium complex II, there is hydrogen bonding between the benzoic acid moiety and a disordered co-crystallized THF molecule. In the crystal, the molecules are linked by C—H...Cl hydrogen bonds, forming layers parallel to (100 separated by layers of THF solvent molecules.

Kavalactones and benzoic acid derivatives from leaves of Piper fuligineum Kunth (Piperaceae)

Energy Technology Data Exchange (ETDEWEB)

Mazzeu, Bruna F.; Felippe, Lidiane G.; Furlan, Maysa, E-mail: maysaf@iq.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil); Cotinguiba, Fernando [Universidade Federal do Rio de Janeiro (IPPN/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pesquisas de Produtos Naturais; Kato, Massuo J. [Universidade de São Paulo (USP), SP (Brazil). Instituto de Química

2018-05-01

The known kavalactones (E)-4-methoxy-6-styryl-2H-pyran-2-one, 4-methoxy6-(3-phenyloxiran-2-yl)-2H-pyran-2-one, 6-(1,2-dihydroxy-2-phenylethyl)-4-methoxy-2H-pyran2-one, the three benzoic acid derivatives methyl-4-methoxy-3-(3'-methyl-2'-butenyl)benzoate and methyl 2,2-dimethyl-4-oxochroman-6-carboxylate, and a new methyl 4-methoxy-3-(3-methylbut2-enoyl)benzoate were isolated from the ethanolic extract of Piper fuligineum. The structures of these compounds were determined by using a combination of spectroscopic methods, including 1D- and 2D-nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. This is the first report of the chemical study of P. fuligineum, and the methyl 4-methoxy-3-(3-methylbut2-enoyl)benzoate is described as a new natural product. (author)

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.

Thermodynamic properties of isomeric iso-butoxybenzoic acids: Experimental and theoretical study

International Nuclear Information System (INIS)

Jakubczyk, Michał; Sporzyński, Andrzej; Emel’yanenko, Vladimir N.; Varfolomeev, Mikhail A.; Verevkin, Sergey P.

2015-01-01

Highlights: • Vapor pressures of butoxy benzoic acid derivatives were measured. • Vaporization, sublimation and fusion enthalpies were derived. • Molar enthalpies of formation were measured by calorimetry. • Thermochemical data tested for consistency using additivity rules and computations. • Simple additivity method suggested for prediction thermochemical properties. - Abstract: Standard (p° = 0.1 MPa) molar enthalpies of formation at the temperature T = 298.15 K of the 2-, 3-, and 4-iso-butoxybenzoic acids were measured using the combustion calorimetry. Standard molar enthalpies of vaporization and sublimation were derived from the vapor pressure temperature dependencies measured by the transpiration method. Molar enthalpies of the solid state phase transitions were measured by the DSC. Thermodynamic data on alkoxy substituted benzoic acids available in the literature were collected and combined with own experimental results. This data set on alkoxybenzoic acids was evaluated by using quantum-chemical and group-additivity methods

Thermodynamic properties of isomeric iso-butoxybenzoic acids: Experimental and theoretical study

Energy Technology Data Exchange (ETDEWEB)

Jakubczyk, Michał; Sporzyński, Andrzej [Faculty of Chemistry, Warsaw University of Technology, 00-664 Warszawa (Poland); Emel’yanenko, Vladimir N.; Varfolomeev, Mikhail A. [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Department of Physical Chemistry and Department, Science and Technology of Life, Light and Matter, University of Rostock, D-18059 Rostock (Germany)

2015-09-10

Highlights: • Vapor pressures of butoxy benzoic acid derivatives were measured. • Vaporization, sublimation and fusion enthalpies were derived. • Molar enthalpies of formation were measured by calorimetry. • Thermochemical data tested for consistency using additivity rules and computations. • Simple additivity method suggested for prediction thermochemical properties. - Abstract: Standard (p° = 0.1 MPa) molar enthalpies of formation at the temperature T = 298.15 K of the 2-, 3-, and 4-iso-butoxybenzoic acids were measured using the combustion calorimetry. Standard molar enthalpies of vaporization and sublimation were derived from the vapor pressure temperature dependencies measured by the transpiration method. Molar enthalpies of the solid state phase transitions were measured by the DSC. Thermodynamic data on alkoxy substituted benzoic acids available in the literature were collected and combined with own experimental results. This data set on alkoxybenzoic acids was evaluated by using quantum-chemical and group-additivity methods.

Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

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BRATISLAV Ž. JOVANOVIĆ

2009-12-01

Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

N-substituted iminodiacetic acids

International Nuclear Information System (INIS)

Nunn, A.; Loberg, M.

1982-01-01

The chemical preparation of several new N-substituted iminodiacetic acid derivatives are described. These compounds when complexed with sup(99m)Tc provide useful radiopharmaceuticals for the external imaging of the hepatobiliary system. (U.K.)

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

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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.

Substituted Indoleacetic Acids Tested in Tissue Cultures

DEFF Research Database (Denmark)

Engvild, Kjeld Christensen

1978-01-01

Monochloro substituted IAA inhibited shoot induction in tobacco tissue cultures about as much as IAA. Dichloro substituted IAA inhibited shoot formation less. Other substituted IAA except 5-fluoro- and 5-bromoindole-3-acetic acid were less active than IAA. Callus growth was quite variable...

Comparison of salicylic acid, benzoic acid and p-hydroxybenzoic acid for their ability to induce flowering in Lemna Gibba G3

International Nuclear Information System (INIS)

Cleland, F.C.; Kang, B.G.; Khurana, J.P.

1986-01-01

The long-day plant Lemna gibba G3 fails to flower under continuous light on NH 4 + -free 0.5 H medium. This inhibition is completely reversed by 10 μM salicyclic acid (SA) or 32 μM benzoic acid (BA). By contrast, p-hydroxybenzoic acid (p-OH-BA) has virtually no effect on flowering at levels as high as 320 μM. Uptake rates for the three compounds are comparable. Competition studies using 14 C-SA indicate that, compared to SA, BA is about 10-fold less effective and p-OH-BA is nearly 100-fold less effective in competing against 14 C-SA uptake. Both the effectiveness of SA for inducing flowering and the uptake of 14 C-SA are substantially increased as the pH of the medium is lowered from 8 to 4.5. Under a nitrogen atmosphere the uptake of 14 C-SA is partially inhibited above pH 5. Phosphate metabolism may be important for flowering since increasing the phosphate level in the medium 10-15 fold results in substantial flowering, and suboptimal levels of Sa and phosphate interact synergistically to stimulate flowering. The interaction of phosphate with BA and p-OH-BA will be presented

Radiometric titration of officinal radiopharmaceuticals using radioactive kryptonates as end-point indicators. I. Salicylic, acetylosalicylic, benzoic acids

Energy Technology Data Exchange (ETDEWEB)

Toelgyessy, J; Dillinger, P [Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia). Chemickotechnologicka Fakulta; Harangozo, M; Jombik, J [Komenskeho Univ., Bratislava (Czechoslovakia). Farmaceuticka Fakulta

1980-01-01

A method for the determination of salicylic, acetylsalicylic and benzoic acids in officinal pharmaceutical based on radiometric titration with 0.1 mol.l/sup -1/ NaOH was developed. The end-point was detected with the aid of radioactive glass kryptonate. After the end-point, the excess titrant attacks the glass surface layers and this results in releasing /sup 85/Kr, and consequently, in decreasing the radioactivity of the kryptonate employed. The radioactive kryptonate used as an indicator was prepared by the bombardment of glass with accelerated /sup 85/Kr ions. The developed method is simple, accurate and correct.

Amino acid "little Big Bang": representing amino acid substitution matrices as dot products of Euclidian vectors.

Science.gov (United States)

Zimmermann, Karel; Gibrat, Jean-François

2010-01-04

Sequence comparisons make use of a one-letter representation for amino acids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of amino acid intrinsic properties consistent with the substitution matrices. We present a Euclidian vector representation of the amino acids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of amino acid vectors. We apply this vector encoding to the study of the relative importance of various amino acid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. This vector encoding introduces a Euclidian metric in the amino acid space, consistent with substitution matrices. Such a numerical description of the amino acid is useful when intrinsic properties of amino acids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

Amino acid "little Big Bang": Representing amino acid substitution matrices as dot products of Euclidian vectors

Directory of Open Access Journals (Sweden)

Zimmermann Karel

2010-01-01

Full Text Available Abstract Background Sequence comparisons make use of a one-letter representation for amino acids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of amino acid intrinsic properties consistent with the substitution matrices. Results We present a Euclidian vector representation of the amino acids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of amino acid vectors. We apply this vector encoding to the study of the relative importance of various amino acid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. Conclusions This vector encoding introduces a Euclidian metric in the amino acid space, consistent with substitution matrices. Such a numerical description of the amino acid is useful when intrinsic properties of amino acids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

Nucleated Poly(L-lactic acid) with N, N‧-oxalyl bis(benzoic acid) dihydrazide

Science.gov (United States)

Tian, Liang-Liang; Cai, Yan-Hua

2018-04-01

One of the major challenges in the field of Poly(L-lactic acid) (PLLA) is the enhancement of crystallization. In the present work, the evaluation of the influence of N, N‧-oxalyl bis(benzoic acid) dihydrazide (TBOD), as a novel organic nucleating agent, on the non-isothermal crystallization, melting behavior, and thermal stability of PLLA was performed using differential scanning calorimeter and thermogravimetric analysis. Non-isothermal crystallization measurement revealed that TBOD had an excellent accelerating effect for the crystallization of PLLA in cooling, and upon the addition of 3 wt% TBOD, PLLA exhibited the highest onset crystallization temperature and the crystallization peak temperature, as well as the largest non-isothermal crystallization enthalpy. In particular, when the TBOD concentration was 1 wt% ∼ 3 wt%, the onset crystallization temperatures were higher than the theoretical ceiling temperature of crystallization, thoroughly demonstrating the powerful crystallization promoting ability of TBOD. Additionally, the non-isothermal crystallization behavior of PLLA/TBOD depended on the TBOD concentration, cooling rate as well as the final melting temperature. The melting behavior of PLLA/TBOD after non-isothermal crystallization further confirmed the effect of TBOD on the crystallization process and crystal structure of PLLA, and the appearance of the double melting peaks during melting stages was attribute to the melting-recrystallization. For melting behavior after isothermal crystallization, the crystallization temperature and crystallization time significantly affected the melting behavior of PLLA/TBOD. The addition of TBOD could not change the thermal decomposition profile of the PLLA, but the thermal stability did not regularly decrease with increasing of TBOD concentration, indicating that there might exist intermolecular interaction between PLLA and TBOD.

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

-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...... chromatography. Probe depth was measured by 20-MHz ultrasound scanning. The area under the time-versus-concentration curve (AUC) describes the drug exposure in the tissue during the experiment and is a relevant parameter to compare for the 3 dermal probe depths investigated. The AUC(0-12) were: superficial...... significantly different from each other (p value paper demonstrates that there is an inverse relationship between the depth of the probe in the dermis and the amount of drug sampled following topical penetration ex vivo. The result is of relevance to the in vivo situation, and it can...

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.

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

International Nuclear Information System (INIS)

Xiong, Pingping; Li, Jie; Bu, Huaiyu; Wei, Qing; Zhang, Ruolin; Chen, Sanping

2014-01-01

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 0.5 L] n (1), [Cu(HL) 2 Cl 2 ] n (2), [Cu(HL) 2 Cl 2 (H 2 O)] (3), [Cu(L) 2 (H 2 O)] n (4) and [Cu(L)(phen)(HCO 2 )] 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. - 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

Functionalization of Chitosan with 3,4,5-Trihydroxy Benzoic Acid Moiety for The Uptake of Chromium Species

Directory of Open Access Journals (Sweden)

Akhmad Sabarudin

2013-03-01

Full Text Available Chitosan-based chelating resin, the cross-linked chitosan functionalized with 3,4,5-trihydroxy benzoic acid moiety (CCTS-THBA resin, was newly synthesized and its adsorption behavior toward appropriate elements was investigated. At pH 5-9, the CCTS-THBA resin showed quantitative adsorption (87-91% for Cr (VI, while only < 15% for Cr (III. The addition of cyclohexanediamine tetraacetic acid (CyDTA to the samples resulted in a considerably increase of the adsorption of both chromium species. In this condition, Cr (III is chelated with CyDTA to form anionic complexes at pH 3-5, which was then completely adsorbed on the resin by ion exchange mechanism. Similarly, the adsorption of Cr (VI reached almost 100% in pH range of 3-6. The adsorption capacity of CCTS-THBA resin for Cr (VI was 109 mg g-1.

Do carboximide–carboxylic acid combinations form co-crystals? The role of hydroxyl substitution on the formation of co-crystals and eutectics

Directory of Open Access Journals (Sweden)

Ramanpreet Kaur

2015-05-01

Full Text Available Carboxylic acids, amides and imides are key organic systems which provide understanding of molecular recognition and binding phenomena important in biological and pharmaceutical settings. In this context, studies of their mutual interactions and compatibility through co-crystallization may pave the way for greater understanding and new applications of their combinations. Extensive co-crystallization studies are available for carboxylic acid/amide combinations, but only a few examples of carboxylic acid/imide co-crystals are currently observed in the literature. The non-formation of co-crystals for carboxylic acid/imide combinations has previously been rationalized, based on steric and computed stability factors. In the light of the growing awareness of eutectic mixtures as an alternative outcome in co-crystallization experiments, the nature of various benzoic acid/cyclic imide combinations is established in this paper. Since an additional functional group can provide sites for new intermolecular interactions and, potentially, promote supramolecular growth into a co-crystal, benzoic acids decorated with one or more hydroxyl groups have been systematically screened for co-crystallization with one unsaturated and two saturated cyclic imides. The facile formation of an abundant number of hydroxybenzoic acid/cyclic carboximide co-crystals is reported, including polymorphic and variable stoichiometry co-crystals. In the cases where co-crystals did not form, the combinations are shown invariably to result in eutectics. The presence or absence and geometric disposition of hydroxyl functionality on benzoic acid is thus found to drive the formation of co-crystals or eutectics for the studied carboxylic acid/imide combinations.

Evaluating rare amino acid substitutions (RGC_CAMs in a yeast model clade.

Directory of Open Access Journals (Sweden)

Kenneth Polzin

Full Text Available When inferring phylogenetic relationships, not all sites in a sequence alignment are equally informative. One recently proposed approach that takes advantage of this inequality relies on sites that contain amino acids whose replacement requires multiple substitutions. Identifying these so-called RGC_CAM substitutions (after Rare Genomic Changes as Conserved Amino acids-Multiple substitutions requires that, first, at any given site in the amino acid sequence alignment, there must be a minimum of two different amino acids; second, each amino acid must be present in at least two taxa; and third, the amino acids must require a minimum of two nucleotide substitutions to replace each other. Although theory suggests that RGC_CAM substitutions are expected to be rare and less likely to be homoplastic, the informativeness of RGC_CAM substitutions has not been extensively evaluated in biological data sets. We investigated the quality of RGC_CAM substitutions by examining their degree of homoplasy and internode certainty in nearly 2.7 million aligned amino acid sites from 5,261 proteins from five species belonging to the yeast Saccharomyces sensu stricto clade whose phylogeny is well-established. We identified 2,647 sites containing RGC_CAM substitutions, a number that contrasts sharply with the 100,887 sites containing RGC_non-CAM substitutions (i.e., changes between amino acids that require only a single nucleotide substitution. We found that RGC_CAM substitutions had significantly lower homoplasy than RGC_non-CAM ones; specifically RGC_CAM substitutions showed a per-site average homoplasy index of 0.100, whereas RGC_non-CAM substitutions had a homoplasy index of 0.215. Internode certainty values were also higher for sites containing RGC_CAM substitutions than for RGC_non-CAM ones. These results suggest that RGC_CAM substitutions possess a strong phylogenetic signal and are useful markers for phylogenetic inference despite their rarity.

Protective effect of ketotifen and disodium cromoglycate against bronchoconstriction induced by aspirin, benzoic acid or tartrazine in intolerant asthmatics.

Science.gov (United States)

Wüthrich, B

1979-01-01

Oral challenge tests with acetylsalicylic acid, tartrazine or benzoic acid were performed in 7 intolerant asthmatic patients after a 3-day treatment with either orally taken ketotifen (1 mg twice daily) or inhaled disodium cromoglycate (20 mg four times daily) at random. Protection was noted with ketotifen in 5, with DSCG in 3 patients. On the evaluation of the mean percentage of the maximum decline in the forced expiratory volume in 1 sec (FEV1) only ketotifen afforded significant protection statistically (p less than 0.05). All the intolerant asthmatics studies showed, as an immunological abnormity, a slight, but significant decrease of the C1-inhibitor levels. Moreover, in three out of these the alpha 1-antitrypsin serum values were under the lower normal range.

40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.

Science.gov (United States)

2010-07-01

..., alkali salt. 721.5278 Section 721.5278 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5278 Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical... as a substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to reporting under...

Chromatographic study of highly methoxylated lime pectins deesterified by different pectin methyl-esterases.

Science.gov (United States)

Ralet, M C; Bonnin, E; Thibault, J F

2001-03-25

The inter-molecular distribution of free carboxyl groups of two highly methoxylated pectins enzymatically deesterified by plant and fungus pectin methyl-esterases were investigated by size-exclusion (SEC) and ion-exchange chromatography (IEC). "Homogeneous" populations with respect to molar mass or charge density were thereby obtained and their chemical composition and physico-chemical properties (transport parameter for monovalent cations and calcium, calcium activity coefficient) were studied. Chemical analysis showed that the composition varies from one SEC fraction to another, the highest molar mass fraction being richer in rhamnose and galactose and exhibiting a slightly higher degree of methylation. Separation of pectins by IEC revealed a quite homogeneous charge density distribution for F58 contrary to P60 which exhibited a large distribution of methoxyl groups. The free carboxyl groups distributions and calcium binding behaviours of SEC and IEC fractions were shown to differ widely for highly methoxylated pectins deesterified by plant and fungus pectin methyl-esterases.

Oxidation of phenolic acid derivatives by soil and its relevance to allelopathic activity.

Science.gov (United States)

Ohno, T

2001-01-01

Previous studies have suggested that phenolic acids from legume green manures may contribute to weed control through allelopathy. The objectives of this study were to investigate the oxidation reactions of phenolic acids in soil and to determine the subsequent effects of oxidation upon phytotoxicity. Soils were reacted for 18 h with 0.25 mmol L(-1) benzoic and cinnamic acid derivative solutions and Mn release from the suspension was used as a marker for phenolic acid oxidation. The extent of oxidation in soil suspensions was in the order of 3,4dihydroxy- > 4-hydroxy-3-methoxy- > 4-hydroxy-approximately 2-hydroxy-substituted benzoic and cinnamic acids. The same ranking was observed for cyclic voltammetry peak currents of the cinnamic acid derivatives. This suggests that the oxidation of phenolic acids is controlled by the electron transfer step from the sorbed phenolic acid to the metal oxide. A bioassay experiment showed that the 4-hydroxy-, 4-hydroxy-3-methoxy-, and 3,4-dihydroxy-substituted cinnamic acids were bioactive at 0.25 mmol L(-1) concentration. Reaction with soil for 18 h resulted in the elimination of bioactivity of these three cinnamic acids at the 5% significance level. The oxidative reactivity of phenolic acids may limit the potential of allelopathy as a component of an integrated weed management system. However, the initial phytotoxicity after soil incorporation may coincide with the early, critical stage of weed emergence and establishment, so that allelopathic phenolic acids may still play a role in weed management despite their reactivity in soil systems.

Amino propynyl benzoic acid building block in rigid spacers of divalent ligands binding to the Syk SH2 domains with equally high affinity as the natural ligand

NARCIS (Netherlands)

Dekker, Frank J; de Mol, Nico J; Fischer, Marcel J E; Liskamp, Rob M J; Dekker, Frank

2003-01-01

The construction of rigid spacers composed of amino propynyl benzoic acid building blocks is described. These spacers were used to link two phosphopeptide ligand sites towards obtaining divalent ligands with a high affinity for Syk tandem SH2 domains, which are important in signal transduction. The

Studies on the structure of industrial high methoxyl pectins

NARCIS (Netherlands)

Kravtchenko, T.P.

1992-01-01

The chemical structure of three industrial high methoxyl pectins (one extracted from apple pomace and two from lemon peels) has been extensively investigated. The apple pectin differs from the lemon ones by having a higher apparent molecular size, a higher neutral-sugar content, present

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.

Amino acid substitutions in random mutagenesis libraries: lessons from analyzing 3000 mutations.

Science.gov (United States)

Zhao, Jing; Frauenkron-Machedjou, Victorine Josiane; Kardashliev, Tsvetan; Ruff, Anna Joëlle; Zhu, Leilei; Bocola, Marco; Schwaneberg, Ulrich

2017-04-01

The quality of amino acid substitution patterns in random mutagenesis libraries is decisive for the success in directed evolution campaigns. In this manuscript, we provide a detailed analysis of the amino acid substitutions by analyzing 3000 mutations of three random mutagenesis libraries (1000 mutations each; epPCR with a low-mutation and a high-mutation frequency and SeSaM-Tv P/P) employing lipase A from Bacillus subtilis (bsla). A comparison of the obtained numbers of beneficial variants in the mentioned three random mutagenesis libraries with a site saturation mutagenesis (SSM) (covering the natural diversity at each amino acid position of BSLA) concludes the diversity analysis. Seventy-six percent of the SeSaM-Tv P/P-generated substitutions yield chemically different amino acid substitutions compared to 64% (epPCR-low) and 69% (epPCR-high). Unique substitutions from one amino acid to others are termed distinct amino acid substitutions. In the SeSaM-Tv P/P library, 35% of all theoretical distinct amino acid substitutions were found in the 1000 mutation library compared to 25% (epPCR-low) and 26% (epPCR-high). Thirty-six percent of distinct amino acid substitutions found in SeSaM-Tv P/P were unobtainable by epPCR-low. Comparison with the SSM library showed that epPCR-low covers 15%, epPCR-high 18%, and SeSaM-Tv P/P 21% of obtainable beneficial amino acid positions. In essence, this study provides first insights on the quality of epPCR and SeSaM-Tv P/P libraries in terms of amino acid substitutions, their chemical differences, and the number of obtainable beneficial amino acid positions.

Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group-Determination of Dissolved Isoxaflutole and Its Sequential Degradation Products, Diketonitrile and Benzoic Acid, in Water Using Solid-Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry

Science.gov (United States)

Meyer, Michael T.; Lee, Edward A.; Scribner, Elisabeth A.

2007-01-01

An analytical method for the determination of isoxaflutole and its sequential degradation products, diketonitrile and a benzoic acid analogue, in filtered water with varying matrices was developed by the U.S. Geological Survey Organic Geochemistry Research Group in Lawrence, Kansas. Four different water-sample matrices fortified at 0.02 and 0.10 ug/L (micrograms per liter) are extracted by vacuum manifold solid-phase extraction and analyzed by liquid chromatography/tandem mass spectrometry using electrospray ionization in negative-ion mode with multiple-reaction monitoring (MRM). Analytical conditions for mass spectrometry detection are optimized, and quantitation is carried out using the following MRM molecular-hydrogen (precursor) ion and product (p) ion transition pairs: 357.9 (precursor), 78.9 (p), and 277.6 (p) for isoxaflutole and diketonitrile, and 267.0 (precursor), 159.0 (p), and 223.1 (p) for benzoic acid. 2,4-dichlorophenoxyacetic acid-d3 is used as the internal standard, and alachlor ethanesulfonic acid-d5 is used as the surrogate standard. Compound detection limits and reporting levels are calculated using U.S. Environmental Protection Agency procedures. The mean solid-phase extraction recovery values ranged from 104 to 108 percent with relative standard deviation percentages ranging from 4.0 to 10.6 percent. The combined mean percentage concentration normalized to the theoretical spiked concentration of four water matrices analyzed eight times at 0.02 and 0.10 ug/L (seven times for the reagent-water matrix at 0.02 ug/L) ranged from approximately 75 to 101 percent with relative standard deviation percentages ranging from approximately 3 to 26 percent for isoxaflutole, diketonitrile, and benzoic acid. The method detection limit (MDL) for isoxaflutole and diketonitrile is 0.003 ug/L and 0.004 ug/L for benzoic acid. Method reporting levels (MRLs) are 0.011, 0.010, and 0.012 ug/L for isoxaflutole, diketonitrile, and benzoic acid, respectively. On the basis

D77, one benzoic acid derivative, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular LEDGF/p75

International Nuclear Information System (INIS)

Du Li; Zhao Yaxue; Chen, Jing; Yang Liumeng; Zheng Yongtang; Tang Yun; Shen Xu; Jiang Hualiang

2008-01-01

Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-factor for integration. Since LEDGF/p75 plays an important role in HIV integration, disruption of the LEDGF/p75 interaction with IN has provided a special interest for anti-HIV agent discovery. In this work, we reported that a benzoic acid derivative, 4-[(5-bromo-4-{[2,4-dioxo-3-(2-oxo-2-phenylethyl) -1,3-thiazolidin-5-ylidene]methyl}-2-ethoxyphenoxy)methyl]benzoic acid (D77) could potently inhibit the IN-LEDGF/p75 interaction and affect the HIV-1 IN nuclear distribution thus exhibiting antiretroviral activity. Molecular docking with site-directed mutagenesis analysis and surface plasmon resonance (SPR) binding assays has clarified possible binding mode of D77 against HIV-1 integrase. As the firstly discovered small molecular compound targeting HIV-1 integrase interaction with LEDGF/p75, D77 might supply useful structural information for further anti-HIV agent discovery

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. Copyright © 2011 Wiley Periodicals, Inc.

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. Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.

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

International Nuclear Information System (INIS)

Paez, Julieta I.; Strumia, Miriam C.; Passeggi, Mario C.G.; Ferron, Julio; Baruzzi, Ana M.; Brunetti, Veronica

2009-01-01

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 2 ) onto carbon surfaces showing a simple and rapid way to produce conductive surfaces with electroactive chemical functions. The immobilized D-NO 2 layer has been characterized using atomic force microscopy and cyclic voltammetry. D-NO 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 3 ) 6 3+ /Ru(NH 3 ) 6 2+ and Fe(CN) 6 3- /Fe(CN) 6 4- . Electrocatalytic oxidation of nicotinamide adenine dinucleotide onto a modified carbon surface was also observed.

CodonTest: modeling amino acid substitution preferences in coding sequences.

Directory of Open Access Journals (Sweden)

Wayne Delport

2010-08-01

Full Text Available Codon models of evolution have facilitated the interpretation of selective forces operating on genomes. These models, however, assume a single rate of non-synonymous substitution irrespective of the nature of amino acids being exchanged. Recent developments have shown that models which allow for amino acid pairs to have independent rates of substitution offer improved fit over single rate models. However, these approaches have been limited by the necessity for large alignments in their estimation. An alternative approach is to assume that substitution rates between amino acid pairs can be subdivided into rate classes, dependent on the information content of the alignment. However, given the combinatorially large number of such models, an efficient model search strategy is needed. Here we develop a Genetic Algorithm (GA method for the estimation of such models. A GA is used to assign amino acid substitution pairs to a series of rate classes, where is estimated from the alignment. Other parameters of the phylogenetic Markov model, including substitution rates, character frequencies and branch lengths are estimated using standard maximum likelihood optimization procedures. We apply the GA to empirical alignments and show improved model fit over existing models of codon evolution. Our results suggest that current models are poor approximations of protein evolution and thus gene and organism specific multi-rate models that incorporate amino acid substitution biases are preferred. We further anticipate that the clustering of amino acid substitution rates into classes will be biologically informative, such that genes with similar functions exhibit similar clustering, and hence this clustering will be useful for the evolutionary fingerprinting of genes.

Elucidation of the substitution pattern of 9,10-anthraquinones through the chemical shifts of peri-hydroxyl protons

DEFF Research Database (Denmark)

Schripsema, Jan; Danigno, Denise

1996-01-01

In 9,10-anthraquinones the chemical shift of a peri-hydroxyl proton is affected by the substituents in the other benzenoid ring. These effects are additive. They are useful for the determination of substitution patterns and have been used to revise the structures of six previously reported...... anthraquinones containing methoxyl, hydroxyl, methylenedioxy and beta-methyl substituents. Because the chemical shifts of the other protons are hardly affected by substitutions in the other ring, the characteristic chemical shifts for a wide variety of substitution patterns could be derived....

Structural characterization of native high-methoxylated pectin using nuclear magnetic resonance spectroscopy and ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Comparative use of 2,5-dihydroxybenzoic acid and nor-harmane as UV-MALDI matrices.

Science.gov (United States)

Monge, María Eugenia; Negri, R Martín; Kolender, Adriana A; Erra-Balsells, Rosa

2007-01-01

The successful analysis by ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (UV-MALDI-TOF MS) of native and hydrolyzed high-methoxylated pectin samples is described. In order to find the optimal conditions for UV-MALDI-TOF MS analysis several experimental variables were studied such as: different UV-MALDI matrices (nor-harmane, 2,5-dihydroxybenzoic acid), sample preparation methods (mixture, sandwich), inorganic salt addition (doping salts, NaCl, KCl, NH(4)Cl), ion mode (positive, negative), linear and reflectron mode, etc. nor-Harmane has never been used as a UV-MALDI matrix for the analysis of pectins but its use avoids pre-treatment of the sample, such as an enzymatic digestion or an acid hydrolysis, and there is no need to add salts, making the analysis easier and faster. This study suggested an alternative way of analyzing native high-methoxylated pectins, with UV-MALDI-TOF MS, by using nor-harmane as the matrix in negative ion mode. The analysis by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy of the native and hydrolyzed pectin is also briefly described. Copyright (c) 2007 John Wiley & Sons, Ltd.

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. Copyright © 2016 Elsevier B.V. All rights reserved.

Spectroscopic and first principles investigation on 4-[(4-pyridinylmethylene)amino]-benzoic acid bearing pyridyl and carboxyl anchoring groups

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Zhang, Lei; Wang, Qiaoyi

2018-03-01

We report a combined experimental and computational investigation on the structure and photophysics of 4-[(4-pyridinylmethylene)amino]-benzoic acid, a functional molecule bearing two anchoring groups for attachment onto a TiO2 surface and perovskite surface, for potential solar cell application. This molecule possesses interesting adsorption properties in perovskite solar cell because the pyridyl group serves as the Lewis base and targets Lewis acidic sites in the perovskite surface, while the carboxyl group targets TiO2 surface, improving the coupling between the perovskite surface and the TiO2 surface. The electronic structures of the molecule and its photochemistry are revealed by the UV-vis absorption spectra and the fluorescence spectra under visible light irradiation, which are combined with density functional theory (DFT) and time-dependent density functional theory (TDDFT) analysis. Considering the bi-anchoring groups and the conjugated π system embedded in the molecule, we anticipate it can molecular engineer the TiO2/perovskite interface in perovskite solar cell.

Ionic liquid [OMIm][OAc] directly inducing oxidation cleavage of the β-O-4 bond of lignin model compounds.

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Yang, Yingying; Fan, Honglei; Meng, Qinglei; Zhang, Zhaofu; Yang, Guanying; Han, Buxing

2017-08-03

We explored the oxidation reactions of lignin model compounds directly induced by ionic liquids under metal-free conditions. In this work, it was found that ionic liquid 1-octyl-3-methylimidazolium acetate as a solvent could promote the aerobic oxidation of lignin model compound 2-phenoxyacetophenone (1) and the yields of phenol and benzoic acid from 1 could be as high as 96% and 86%, respectively. A possible reaction pathway was proposed based on a series of control experiments. An acetate anion from the ionic liquid attacked the hydrogen from the β-carbon thereby inducing the cleavage of the C-O bond of the aromatic ether. Furthermore, it was found that 2-(2-methoxyphenoxy)-1-phenylethanone (4) with a methoxyl group could also be transformed into aromatic products in this simple reaction system and the yields of phenol and benzoic acid from 4 could be as high as 98% and 85%, respectively. This work provides a simple way for efficient transformation of lignin model compounds.

Effect of substitution of low linolenic acid soybean oil for hydrogenated soybean oil on fatty acid intake.

Science.gov (United States)

DiRienzo, Maureen A; Astwood, James D; Petersen, Barbara J; Smith, Kim M

2006-02-01

Low linolenic acid soybean oil (LLSO) has been developed as a substitute for hydrogenated soybean oil to reduce intake of trans FA while improving stability and functionality in processed foods. We assessed the dietary impact of substitution of LLSO for hydrogenated soybean oil (HSBO) used in several food categories. All substitutions were done using an assumption of 100% market penetration. The impact of this substitution on the intake of five FA and trans FA was assessed. Substitution of LLSO for current versions of HSBO resulted in a 45% decrease in intake of trans FA. Impacts on other FA intakes were within the realm of typical dietary intakes. No decrease in intake of alpha-linolenic acid was associated with the use of LLSO in place of HSBO because LLSO substitutes for HSBO that are already low in alpha-linolenic acid.

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.

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.

Aromatic products from reaction of lignin model compounds with UV-alkaline peroxide

International Nuclear Information System (INIS)

Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

1997-01-01

A series of guaiacyl and syringyl lignin model compounds and their methylated analogues were reacted with alkaline hydrogen peroxide while irradiating with UV light at 254 nm. The aromatic products obtained were investigated by gas chromatography-mass spectrometry (GC-MS). Guaiacol, syringol and veratrol gave no detectable aromatic products. However, syringol methyl ether gave small amounts of aromatic products, resulting from ring substitution and methoxyl displacement by hydroxyl radicals. Reaction of vanillin and syringaldehyde gave the Dakin reaction products, methoxy-1,4-hydroquinones, while reaction of their methyl ethers yielded benzoic acids. Acetoguaiacone, acetosyringone and their methyl ethers afforded several hydroxylated aromatic products, but no aromatic products were identified in the reaction mixtures from guaiacylpropane and syringylpropane. In contrast, veratrylpropane gave a mixture from which 17 aromatic hydroxylated compounds were identified. It is concluded that for phenolic lignin model compounds, particularly those possessing electrondonating aromatic ring substituents, ring-cleavage reactions involving superoxide radical anions are dominant, whereas for non-phenolic lignin models, hydroxylation reactions through attack of hydroxyl radicals prevail

Presença dos ácidos benzóico e sórbico em vinhos e sidras produzidos no Brasil Presence of benzoic and sorbic acids in Brazilian wines and ciders

Directory of Open Access Journals (Sweden)

Rita Margarete Donato Machado

2007-12-01

Full Text Available O objetivo do presente trabalho foi a determinação dos níveis de ácido benzóico e ácido sórbico em uma variedade de vinhos e sidras brasileiros, de modo a comparar os valores com os máximos permitidos pela legislação. Um total de 49 amostras (sendo 35 vinhos tintos, 11 vinhos brancos e 3 sidras, disponíveis comercialmente, foram analisadas por CLAE com detector de arranjo de diodos. Apesar do uso de ácido benzóico em vinhos e sidras não ser permitido, esse conservador foi detectado em 3 amostras: 1 vinho e 2 sidras em níveis de 295,6, 424,7 e 608,4 mg.L-1, respectivamente. O ácido sórbico foi detectado em 49% das amostras analisadas com níveis variando de 91,0 a 309,5 mg.L-1. Considerando apenas as amostras nas quais o ácido sórbico foi detectado, o valor médio encontrado foi de 171,2 mg.L-1. Em seis amostras de vinho tinto os níveis de ácido sórbico estavam acima do permitido pela legislação brasileira. Os resultados encontrados no presente trabalho mostram que em algumas amostras, os níveis dos ácidos benzóico e sórbico nos vinhos e sidras analisados, assim como a rotulagem desses produtos não estão de acordo com a legislação vigente no Brasil.This study determined benzoic and sorbic acid contents in Brazilian wines and ciders in order to verify whether these preservatives are used in accordance with Brazilian regulations. Forty-nine samples of commercially available wines (35 red wines, 11 white wines and 3 ciders were analyzed by HPLC coupled to a photodiode array detector. Although the use of benzoic acid in wines and ciders is not permitted, this preservative was detected in three samples, one wine and two ciders, which contained benzoic acid levels of 295.6, 424.7 and 608.4 mg.L-1, respectively. Sorbic acid was detected in 49% of the analyzed samples, with levels ranging from 91.0 to 309.5 mg.L-1. Considering only the samples containing sorbic acid, the mean content detected was 171.2 mg.L-1. Six red wine

Thermometric titration of acids in pyridine.

Science.gov (United States)

Vidal, R; Mukherjee, L M

1974-04-01

Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

Natural derivatives of diphenolic acid as substitutes for bisphenol-A

Science.gov (United States)

Ertl, Johanna; Cerri, Elisa; Rizzuto, Matteo; Caretti, Daniele

2014-05-01

Diphenolic acid had been originally used in the first epoxy resins and was later on forgotten as it was substituted by the cheaper bisphenol A. But in the recent years major health concerns have been raised as bisphenol A has a pseudo-hormonal effect on the body, playing the role of estrogen it can cause a severe impact on the organism, especially in males. Moreover it is produced from acetone and phenol, both from fossil, and thus limited resources. On the contrary, diphenolic acid is synthesized from levulinic acid and phenol. Levulinic acid being directly produced by hydrolysis of biomass. By substituting the fossil phenol with natural phenols from lignin or plant extraction we are able to synthesize a fully renewable substitute for bisphenol A. The reactions to yield an epoxy resin have been examined and the reactivity with epichlorohydrin is satisfying. Moreover, some of the derivatives of diphenolic acid have interesting curing properties and preliminary results show excellent properties of the cured resin, including thermal stability and pencil hardness.

Amino acid derived 1,4-dialkyl substituted imidazolones

DEFF Research Database (Denmark)

Diness, Frederik; Meldal, Morten Peter

2010-01-01

A general method for synthesis of 1,4-substituted imidazolones from amino acids on solid support or in solution has been developed. Amino acid derived 3-Boc-(1,3)-oxazinane (Box) protected amino aldehyde building blocks were coupled through urea bonds to the amino terminal of dipeptides or amino...... acids. Upon acidic release, the aldehyde instantaneously formed the cyclic N-carbamyliminium ion, which rearranged to the corresponding imidazolone. Under strongly acidic conditions the imidazolones acted as nuclophiles in the Pictet-Spengler reaction....

Photoinduced Birefringent Pattern and Photoinactivation of Liquid-Crystalline Copolymer Films with Benzoic Acid and Phenylaldehyde Side Groups.

Science.gov (United States)

Kawatsuki, Nobuhiro; Inada, Shogo; Fujii, Ryosuke; Kondo, Mizuho

2018-02-06

In situ formation of N-benzylideneaniline (NBA) side groups achieved photoinduced cooperative reorientation of photoinactive copolymers with phenylaldehyde (PA) and benzoic acid (BA) side groups doped with 4-methoxyaniline (AN) molecules. Thermally stimulated molecular reorientation of the side groups was generated due to the axis-selective photoreaction of the NBA moieties. Selective coating with AN on the copolymer film formed NBA moieties in the desired region, resulting in a photoinduced birefringent pattern. Additionally, postannealing at an elevated temperature for a long time attained photoinactivation of the reoriented film, and recoating with AN to form NBA achieved the multiple birefringent patterns and repatterning of the reoriented structures. The slow thermal hydrolysis of NBA, which was 50 times slower than the thermally stimulated self-organization of the side groups due to the presence of BA side groups, contributed to the photodurability of the reoriented film and multiple birefringent patterns.

4- 18F]fluoroarylalkylethers via an improved synthesis of n.c.a. 4- 18F]fluorophenol

International Nuclear Information System (INIS)

Ludwig, Thomas; Ermert, Johannes; Coenen, Heinz H.

2002-01-01

This paper describes the improved synthesis of n.c.a. 4- 18 F]fluorophenol for the preparation of 18 F-labeled alkylarylethers. Nucleophilic fluorination of substituted benzophenone derivatives yielded n.c.a. 4- 18 F]fluoro-4'-substituted benzophenones with 80- 90 % RCY, which were converted to benzoic acid phenylesters by treatment with peracetic acid. Strong electron-withdrawing substituents like nitro, cyano and trifluoromethyl favor a fluorophenyl-to-oxygen migration resulting in the formation of corresponding benzoic acid fluorophenylesters. N.c.a. 18 F]fluorophenol is almost quantitatively formed after hydrolysis and can easily be converted with alkylhalides into n.c.a. 18 F]fluoroarylalkylethers

4- {sup 18}F]fluoroarylalkylethers via an improved synthesis of n.c.a. 4- {sup 18}F]fluorophenol

Energy Technology Data Exchange (ETDEWEB)

Ludwig, Thomas; Ermert, Johannes E-mail: j.ermert@fz-juelich.de; Coenen, Heinz H

2002-02-01

This paper describes the improved synthesis of n.c.a. 4- {sup 18}F]fluorophenol for the preparation of {sup 18}F-labeled alkylarylethers. Nucleophilic fluorination of substituted benzophenone derivatives yielded n.c.a. 4- {sup 18}F]fluoro-4'-substituted benzophenones with 80- 90 % RCY, which were converted to benzoic acid phenylesters by treatment with peracetic acid. Strong electron-withdrawing substituents like nitro, cyano and trifluoromethyl favor a fluorophenyl-to-oxygen migration resulting in the formation of corresponding benzoic acid fluorophenylesters. N.c.a. {sup 18}F]fluorophenol is almost quantitatively formed after hydrolysis and can easily be converted with alkylhalides into n.c.a. {sup 18}F]fluoroarylalkylethers.

Molecular acidity: An accurate description with information-theoretic approach in density functional reactivity theory.

Science.gov (United States)

Cao, Xiaofang; Rong, Chunying; Zhong, Aiguo; Lu, Tian; Liu, Shubin

2018-01-15

Molecular acidity is one of the important physiochemical properties of a molecular system, yet its accurate calculation and prediction are still an unresolved problem in the literature. In this work, we propose to make use of the quantities from the information-theoretic (IT) approach in density functional reactivity theory and provide an accurate description of molecular acidity from a completely new perspective. To illustrate our point, five different categories of acidic series, singly and doubly substituted benzoic acids, singly substituted benzenesulfinic acids, benzeneseleninic acids, phenols, and alkyl carboxylic acids, have been thoroughly examined. We show that using IT quantities such as Shannon entropy, Fisher information, Ghosh-Berkowitz-Parr entropy, information gain, Onicescu information energy, and relative Rényi entropy, one is able to simultaneously predict experimental pKa values of these different categories of compounds. Because of the universality of the quantities employed in this work, which are all density dependent, our approach should be general and be applicable to other systems as well. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Synthesis and antibacterial activity of some Schiff bases derived from 4-aminobenzoic acid

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JIGNA PAREKH

2005-10-01

Full Text Available The following Schiff bases have been synthesized: (1 4-[(2-chlorobenzylidene amino]benzoic acid [JP1], (2 4-[(furan-2-ylmethyleneamino]benzoic acid [JP2], (3 4-[(3-phenylallylideneamino]benzoic acid [JP3], (4 4-[(2-hydroxybenzylidene amino]benzoic acid [JP4], (5 4-[(4-hydroxy-3-methoxybenzylideneamino]benzoic acid [JP5] and (6 4-[(3-nitrobenzylideneamino]benzoic acid [JP6]. They were screened as potential antibacterial agents against a number of medically important bacterial strains. The antibacterial activity was studied against A. faecalis ATCC 8750, E. aerogenes ATCC 13048, E. coli ATCC 25922, K. pneumoniae NCIM 2719, S. aureus ATCC 25923, P. vulgaris NCIM 8313, P. aeruginosa ATCC 27853 and S. typhimurium ATCC 23564. The antibacterial activity was evaluated using the Agar Ditch method. The solvents used were 1,4-dioxane and dimethyl sulfoxide. Different effects of the compounds were found in the bacterial strains investigated and the solvents used, suggesting, once again, that the antibacterial activity is dependent on the molecular structure of the compound, the solvent used and the bacterial strain under consideration. In the present work, 1,4-dioxane proved to be a good solvent in inhibiting the above stated bacterial strains.

(Benzoato-κObis(1,10-phenanthroline-κ2N,N′copper(II chloride benzoic acid disolvate

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Wen-Xiang Huang

2010-05-01

Full Text Available In the title complex, [Cu(C7H5O2(C12H8N22]Cl·2C6H5COOH, the CuII ion is coordinated by one carboxylate O atom from a benzoate anion and four N atoms from two phenantroline ligands in a distorted five-coordinate trigonal-bipyramidal CuON4 chromophore. The Cu2+ and the Cl− ion are imposed by a twofold rotation axiss which also bisects the equally disordered benzoate anion. In the crystal, the molecules are assembled into chains along [010] by C—H...Cl, O—H...Cl and C—H...O hydrogen-bonding interactions. The resulting chains are further connected into two-dimensional supramolecular layers parallel to [100] by interchain π...π stacking interactions [centroid–centroid distance = 3.823 (5 Å] between the phenanthroline ligands and the benzoic acid molecules, and by C—H...O hydrogen-bonding interactions. Strong π...π stacking interactions between adjacent phenantroline ligands [3.548 (4 Å] assemble the layers into a three-dimensional supramolecular architecture.

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

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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.

Stratified systems without organic solvent - new extraction type of macro- and microquantities of metal ions

International Nuclear Information System (INIS)

Dyogtev, M.I.; Alikina, E.N.; Popova, O.N.; Amindjanov, A.A.

2012-01-01

This article describes the results of studies on solubility in four component systems: di anti pyril methane-benzoic (salicylic) acid-HCl-H 2 O, hexyl di anti pyril methane-benzoic (salicylic) acid-HCl-H 2 O at 298 and 323 K. It is defined that stable stratification appears by addition of hydrochloric acid in the concentration range of 3.0-4.9 wt.% HCl. At substitution of di anti pyril methane on hexyl di anti pyril methane the wide range of stratification in the cut of hexyl di anti pyril methane-benzoic (salicylic) acid - 5 wt.% HCl is observes. The possibility of using of stratified systems for quantitative extraction of copper, cadmium, iron, thallium and tin is proposed.

Effects of tempering (annealing), acid hydrolysis, low-citric acid substitution on chemical and physicochemical properties of starches of four yam (Dioscorea spp.) cultivars.

Science.gov (United States)

Falade, Kolawole O; Ayetigbo, Oluwatoyin E

2017-05-01

The effects of tempering (annealing), acid hydrolysis and low-citric acid substitution on chemical and physicochemical properties of starches of four Nigerian yam cultivars were investigated. Crude fat and protein contents of the native starches decreased significantly after the modifications, while nitrogen-free extract increased significantly with acid hydrolysis and citric acid substitution. Acid hydrolysis and low-citric acid substitution reduced the least concentration for gel formation of the starches from 4 to 2% w/v, but tempering had no effect. Swelling power of the starches reduced significantly, and water solubility increased significantly at 75 and 85 °C, especially with acid hydrolysis and low-citric acid substitution. However, tempering significantly reduced starch solubility in the four cultivars. Paste clarity of starches of white (29.17%), water (18.90%), yellow (30.90%) and bitter (10.57%) yams reduced significantly with tempering to 14.43, 11.83, 16.93 and 7.27%, but increased significantly with acid hydrolysis to 41.40, 35.37, 28.77 and 32.33%, and low-citric acid substitution to 36.60, 44.17, 50.67 and 14.33%, respectively. Pasting properties such as peak, trough, breakdown, final, and setback viscosities and peak time of native starches reduced significantly with acid hydrolysis and low-citric acid substitution, however, tempering significantly increased their pasting temperature, peak time, setback and final viscosities.

Amino acid substitution: its use in detection and analysis of genetic variants

International Nuclear Information System (INIS)

Popp, R.A.; Hirsch, G.P.; Bradshaw, B.S.

1979-01-01

Techniques of chemical analysis, amino acid sequencing and autoradiography are being used to study the frequency of incorporation of normally noncoded amino acids into hemoglobins and seminal fluid proteins. We are studying, by the sequencing of radiolabeled proteins followed by the recovery of [ 3 H] isoleucine phenylthiohydantoin by high-performance liquid chromatography, the frequency at which normally noncoded isoleucine is incorporated into hemoglobin because of base-substitution mutations versus translational errors. Irradiation increases the isoleucine content of human hemoglobin and the frequency of substitution of isoleucine for specific amino acids in rabbit hemoglobin. Studies to date indicate that these techniques have been developed sufficiently for initial analysis of the potential of drugs and environmental pollutants to induce base-substitution mutations in mammalian somatic cells

Hydrophosphorylation of substituted alkynes by phosphonic acids

International Nuclear Information System (INIS)

Nifant'ev, E.F.; Solovetskaya, L.A.; Maslennikova, V.I.; Sergeev, N.M.

1987-01-01

Hydrophosphorylation of functionally substituted alkynes by phosphonic acids can be a convenient method for synthesis of functionally substituted mono- and diphosphine oxides. The ease of hydrophosphorylation is determined by the strength of the negative inductive effect of the substituents on the triple bond and the steric factor. The structure of the bis-adducts was confirmed by elementary analysis and the 31 P and 13 C NMR spectra. The 31 P NMR spectrum is an AB two-spin system. The values of the chemical shifts and spin-spin interaction constants 3 J/sub PP/ are in agreement with the data in the literature for similar compounds

The solubilities of benzene polycarboxylic acids in water

International Nuclear Information System (INIS)

Apelblat, Alexander; Manzurola, Emanuel; Abo Balal, Nazmia

2006-01-01

The solubilities in water of all benzene polycarboxylic acids are discussed, using data determined in this work (benzoic, terephthalic, trimellitic, trimesic, and pyromellitic acids) and available from the literature (benzoic, phthalic, isophthalic, terephthalic, hemimellitic, trimelitic, trimesic, mellophanic, prehnitic, pyromellitic, benzene-pentacarboxylic and mellitic acids). The apparent molar enthalpies of solution at the saturation point for these benzene polycarboxylic acids were determined from the temperature dependence of the solubilities

In Vitro Investigation of Self-Assembled Nanoparticles Based on Hyaluronic Acid-Deoxycholic Acid Conjugates for Controlled Release Doxorubicin: Effect of Degree of Substitution of Deoxycholic Acid

Directory of Open Access Journals (Sweden)

Wen-Hao Wei

2015-03-01

Full Text Available Self-assembled nanoparticles based on a hyaluronic acid-deoxycholic acid (HD chemical conjugate with different degree of substitution (DS of deoxycholic acid (DOCA were prepared. The degree of substitution (DS was determined by titration method. The nanoparticles were loaded with doxorubicin (DOX as the model drug. The human cervical cancer (HeLa cell line was utilized for in vitro studies and cell cytotoxicity of DOX incorporated in the HD nanoparticles was accessed by the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. In addition, cellular uptake of fluorescently labeled nanoparticles was also investigated. An increase in the degree of deoxycholic acid substitution reduced the size of the nanoparticles and also enhanced their drug encapsulation efficiency (EE, which increased with the increase of DS. A higher degree of deoxycholic acid substitution also lead to a lower release rate and an initial burst release of doxorubicin from the nanoparticles. In summary, the degree of substitution allows the modulation of the particle size, drug encapsulation efficiency, drug release rate, and cell uptake efficiency of the nanoparticles. The herein developed hyaluronic acid-deoxycholic acid conjugates are a good candidate for drug delivery and could potentiate therapeutic formulations for doxorubicin–mediated cancer therapy.

Synthesis, spectroscopic studies and antimicrobial activity of chelates 2-(acetyloxy)-benzoic acid with transition metals (CR+3, MN+2, NI+2 AND CU+2)

International Nuclear Information System (INIS)

Khan, B.; Mateen, B.; Ahmed, F.; Ahmed, F.

2007-01-01

2-(acetyloxy)-Benzoic acid chelates with Cr+3, Mn+2, Ni+2 and Cu+2 were synthesized and characterized by the melting point, solubility, Fourier Transform Infrared (FT-IR) Spectroscopy, Atomic Absorption Spectroscopy (AAS), X-Ray Diffraction (XRD) method and evaluated by antimicrobial activity. The functional group present in the chelates was determined by Fourier Transform Infrared Spectroscopy, by X-Ray Diffraction analysis crystal data of chelates, their inter-atomic and inter-planer spacing was also determined. The amount of metal in the chelates was estimated by Atomic Absorption Spectroscopy and their Antimicrobial Activity was studied against Pseudomonas aeruginosa, Escherisha coli and Staphylococcus aureus. (author)

Kinetic study of adsorption and degradation of aniline, benzoic acid, phenol, and diuron in soil suspensions

International Nuclear Information System (INIS)

Dao, T.H.; Lavy, T.L.

1987-01-01

Laboratory studies were conducted to investigate the effects of low temperature and accelerated soil-solution contact on soil adsorption of labile organic chemicals. The authors measured the kinetics of adsorption and degradation of 14 C-aniline, 14 C-benzoic acid, 14 C-phenol, and 14 C-diuron in the solution phase at 3 and 22 0 C. In the initial stages of reactions, the adsorption of all four chemicals was instantaneous at both temperatures under accelerated soil and solution mixing. A steady state was observed after the onset of equilibrium for the adsorption reaction for all compounds within 10 to 30 min. Its length varied according to the expected order of susceptibility to microbial degradation, i.e., diuron > aniline > phenol ≥ benzoate. It was apparent that the steady-state period without or in combination with low temperature could be advantageously used to obtain adsorption measurements in microbially active systems. A mechanistic sorption-catalyzed degradation model was evaluated to uncouple mathematically these processes. The model described satisfactorily the disappearance of labile chemicals in soil suspensions. Numerical analysis allowed the concurrent determination of adsorption, desorption, and biodegradation rate coefficients

Proton magnetic resonance studies in solutions of o- and p-hydroxy benzoic acids in dioxan

International Nuclear Information System (INIS)

Arulmozhi, V.; Srinivasa Rao, A.; Balasubramanian, V.

1990-01-01

High resolution proton(NMR) studies were carried out in solutions of o- and p-hydroxy benzoic acids(OHBA and PHBA) in dioxan (D) for several solute concentrations in the range of 0.01 to 0.10 mole fraction (mf). The spectra corresponding to OH and COOH protons could be distinguished in solutions of OHBA in D whereas solution of PHBA in D show only peak in the range of chemical shifts attributable to OH and COOH protons. In the solution of OHBA in dioxan the chemical shift of the proton of the hydroxyl group increases with increase of solute concentration and attains a maximum at a solute concentration of 0.04 mf and then decreases with further increase of solute concentration. For the carboxyl group, the chemical shift increase with increase of solute concentration and attians a maximum at 0.08 mf solute concentration. In solutions of PHBA in D the chemical shift of the single line observed increases with increase of solute concentration and attains a maximum at a solute concentration of 0.05 mf. The data are interpreted as due to formation of hydrogen bonds between the molecule of OHBA and PHBA and dioxan. The proton magnetic relaxation studies in the above solutions also confirm the above findings. (author). 6 refs., 5 figs

NMR study of the epoxidation of liquid hydrolyzed poly-butadiene and meta-chloro-per-benzoic acid; Estudo atraves de RMN da reacao de epoxidacao de polibutadieno liquido hidroxilado (PBLH) e acido m-cloro perbenzoico (AMCPB)

Energy Technology Data Exchange (ETDEWEB)

Aguiar, Marcelo [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Akcelrud, L [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica; Menezes, Sonia Cabral de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

1994-12-31

This work presents a study concerning the selectivity of the different configurations of the double bond present in liquid hydrolyzed poly-butadiene towards the epoxidation reaction with meta-chloro-per-benzoic acid through hydrogen-1, carbon-13 NMR aiming the production of new materials, varying the epoxidation level 12 refs., 7 figs., 4 tabs.

Allelopathic activity of Leonurus siribicus L. on seed germination and seedling growth of wheat and identification of 4- hydroxy benzoic acid as an allelochemical by chromatography

International Nuclear Information System (INIS)

Sayed, M. A.; Imam, R.; Siddiqui, M.N.

2016-01-01

The aim of this study was to investigate the allelopathic effects of L. siribicus extract on seed germination and seedlings growth of wheat as well as to identify potential allelochemical. The different concentration (5, 10 and 15%) of aqueous extract were applied during the time of sowing and at 5 days after sowing of wheat seed. L. siribicus extract showed concentration and time - depending activity. Different concentration of aqueous extract inhibited seed germination, seedlings growth, when extracts were applied during the time of seed sowing. The stimulatory effect of seedlings growth were found for 5 % aqueous extract, in contrast 10 and 15% extract inhibited seedlings growth, when extracts were applied at 5 days after sowing. Apart from, 4-hydroxy benzoic acids affected seedlings growth irrespective of application time. The weight of dry matter of wheat seedlings were increased for 5% than 10 and 15% extracts. Thin layer chromatography suggested that the presence of 4-hydroxy benzoic acid including other allelopathic and growth regulatory compounds inhibited germination and seedlings growth. Mineral composition was determined and its might have some stimulatory effect on seedlings growth. It was interesting that 5% extract inhibited germination and seedlings growth, when it was applied during the time of seed sowing, but stimulated seedling growth, when it was applied at 5 days after sowing. The extract of this plants can be used either for bioherbicide as well as growth stimulatory agents for the organic farming system. To find out molecular mechanism behind it, further research is to be done. (author)

Is the fenamate group a polymorphophore?: contrasting the crystal energy landscapes of fenamic and tolfenamic acids

NARCIS (Netherlands)

Uzoh, O.G.; Cruz-Cabeza, A.J.; Price, S. L.

2012-01-01

The concept of a polymorphophore was investigated by contrasting the crystal energy landscapes of monomorphic fenamic acid (2-(phenylamino)-benzoic acid, FA) and one of its highly polymorphic derivatives, tolfenamic acid (2-[(3-chloro-2-methylphenyl)amino]-benzoic acid, TA). The crystal energy

Potentiometric titrations of para and nitro substituted aromatic acids and their mixtures in methylethyl ketone

International Nuclear Information System (INIS)

Ozeroglu, C.; Karahan, M.

2011-01-01

In this study, it was the purpose to examine the potentiometric titrations of para and nitro substituted aromatic acids in methylethyl ketone (MEK) as a non-aqueous solvent. Good analytical results were obtained in determining the amount of each acid and the amounts of acids in their ternary mixtures by using 0.0964 N tetrabuthylammoniumhydroxyde (TBAH) as a standard titrant. Methylethyl ketone (MEK) which is a good solvent for many organic compounds and has a convenient liquid range of -86 to 80 deg. C was used for titration of the para and nitro substituted aromatic acids. A linear relationship has been found between pKa values of the para and nitro substituted aromatic acids in water and the half neutralization potential (HNP) values determined by potentiometric titration curves of the same acids in MEK. (author)

40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid, reaction product with... Specific Chemical Substances § 721.6181 Fatty acid, reaction product with substituted oxirane, formaldehyde... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

Synthesis, characterization, and subcellular localization studies of amino acid-substituted porphyrinic pigments

Science.gov (United States)

van Diggelen, Lisa; Khin, Hnin; Conner, Kip; Shao, Jenny; Sweezy, Margaretta; Jung, Anna H.; Isaac, Meden; Simonis, Ursula

2009-06-01

Stopping cancer in its path occurs when photosensitizers (PSs) induce apoptotic cell death after their exposure to light and the subsequent formation of reactive oxygen species. In pursuit of our hypothesis that mitochondrial localizing PSs will enhance the efficacy of the photosensitizing process in photodynamic therapy, since they provoke cell death by inducing apoptosis, we synthesized and characterized tetraphenylporphyrins (TPPs) that are substituted at the paraphenyl positions by two amino acids and two fluoro or hydroxyl groups, respectively. They were prepared according to the Lindsey-modified Adler-Longo methodology using trifluoromethanesulfonylchloride (CF3SO2Cl) as a catalyst instead of trifluoroacetic acid. The use of CF3SO2Cl yielded cleaner products in significantly higher yields. During the synthesis, not only the yields and work-up procedure of the TPPs were improved by using CF3SO2Cl as a catalyst, but also a better means of synthesizing the precursor dipyrromethanes was tested by using indium(III) chloride. Column chromatography, HPLC, and NMR spectroscopy were used to separate and characterize the di-amino acid-dihydroxy, or difluoro-substituted porphyrins and to ascertain their purity before subcellular localization studies were carried out. Studies using androgen-sensitive human prostate adenocarcinoma cells LNCaP revealed that certain amino acid substituted porphyrins that are positively charged in the slightly acidic medium of cancer cells are very useful in shedding light on the targets of TPPs in subcellular organelles of cancer cells. Although some of these compounds have properties of promising photosensitizers by revealing increased water solubility, acidic properties, and innate ability to provoke cell death by apoptosis, the cell killing efficacy of these TPPs is low. This correlates with their subcellular localization. The di-amino acid, di-hydroxy substituted TPPs localize mainly to the lysosomes, whereas the di-fluoro-substituted

Systemic exposure to benzoic acid and hippuric acid following topical application of clindamycin 1%/benzoyl peroxide 3% fixed-dose combination gel in Japanese patients with acne vulgaris.

Science.gov (United States)

Ino, Hiroko; Takahashi, Naoki; Saenz, Alessandra Alio; Wakamatsu, Akira; Hashimoto, Hirofumi; Nakahara, Norie; Hasegawa, Setsuo

2015-01-01

Clindamycin 1%/benzoyl peroxide 3% fixed-dose combination gel (CLDM/BPO3%) is a topical product for the treatment of acne vulgaris. In this study, plasma and urine concentrations of benzoic acid (BA) and hippuric acid (HA) were analyzed to estimate the pharmacokinetics (PK) of BPO after application of CLDM/BPO3% twice-daily for 7 days in Japanese patients with acne vulgaris. Seven-day repeated application of CLDM/BPO3% appears to be safe in this patient population. Concentrations of plasma and urine BA were below the limit of quantification before and after repeated application in most of the 12 adult male patients. Mean difference in Cmax and AUC0-last for plasma HA indicated increased exposures after repeated application, but with wide 90% confidence intervals. Mean Ae0-12 for urine HA was similar before and after repeated application. Repeated application of CLDM/BPO3% is thus unlikely to result in accumulation of BA and HA. The study suggests negligible systemic exposure to BPO metabolites from CLDM/BPO3% after 7-day repeated application in male patients with acne vulgaris. © 2014, The American College of Clinical Pharmacology.

Pd(II)/Bipyridine-Catalyzed Conjugate Addition of Arylboronic Acids to α,β-Unsaturated Carboxylic Acids. Synthesis of β-Quaternary Carbons Substituted Carboxylic Acids.

Science.gov (United States)

Liu, Rui; Yang, Zhenyu; Ni, Yuxin; Song, Kaixuan; Shen, Kai; Lin, Shaohui; Pan, Qinmin

2017-08-04

Pd(II)/bipyridine-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated carboxylic acids (including β,β-disubstituted acrylic acids) was developed and optimized, which provided a mild and convenient method for the highly challenging synthesis of β-quaternary carbons substituted carboxylic acids.

Hydroxyl group induced adsorption of four-nitro benzoic acid on Si(100) 2x1 surface

International Nuclear Information System (INIS)

Ihm, K.; Kang, T.-H.; Hwang, C.C.; Kim, K.-J.; Hwang, H.-N.; Kim, H.-D.; Han, J.H.; Moon, S.; Kim, B.; POSTECH

2004-01-01

Full text: A number of studies have been conducted on self-assembled monolayers (SAMs) in order to study the adhesion of polymer films on various substrates. Recently, the studies on SAMs on the semiconductor substrate are more motivated because of their possible application to nanoscale devices. For the electronic and chemical properties suitable for various applications, the aromatic ring has been used as a building block of various molecules forming SAMs. Here, we used four-nitro benzoic acid (4-NBA) as a model planar aromatic compound, in which the phenyl ring, the carboxylic functional group, and NO2 are on the same plane. The adsorption mechanism of 4-NBA on the in-situ prepared OH/Si(100) 2x1 surface was investigated using x-ray photoelectron spectroscopy and near-edge x-ray absorption e structure. The results revealed that the 4-NBA molecule reacts with the hydroxyl group on the Si(100) 2x1 surface through deprotonation of the carboxyl group. The saturation coverage of 4-NBA estimated by the O 1s ratio is 1/2 ML. Additionally, we could observe the desorption of the oxygen atom from the NO2 moiety of the 4-NBA upon irradiating the surface by photons of 500 eV

Evaluation of sup(99m)Tc labeled amino acids as radiopharmaceuticals, 4. S-substituted cysteines and N-substituted iminodiacetic acids

Energy Technology Data Exchange (ETDEWEB)

Karube, Yoshiharu; Maeda, Tatsuo; Ohya, Masato; Sugata, Setsuro; Kono, Akira (Kyushu Cancer Center Research Inst., Fukuoka (Japan)); Matsushima, Yoshikazu

1982-06-01

Sixteen sup(99m)Tc labeled ligands were evaluated as scintigraphic agents. The ligands studied were cysteine, glutathione, their S-substituted derivatives, lysine-N sup(epsilon), N sup(epsilon)-diacetic acid, glycylglycine-N,N-diacetic acid, glycylglycylglycine-N,N-diacetic acid, taurine-N,N-diacetic acid, hydrazine-N,N-diacetic acid, ethylenediamine-N,N-diacetic acid, and propylne-1,3-diamine-N/sup 1/-,N/sup 1/-diacetic acid. The ligands were labeled with sup(99m)Tc by the SnCl/sub 2/ method with more than 95% yield. The in vivo behavior of the sup(99m)Tc labeled ligands were studied in golden hamsters and dogs. The organ distribution in golden hamsters indicated clearance both by hepatobiliary and renal systems. The pancreas/blood ratios were much lower in the sup(99m)Tc ligands than in /sup 75/Se-selenomethionine. Scintigraphic studies in dogs showed that the liver and kidneys were well visualized but the accumulation by the pancreas was not sufficient for clear visualization.

Dynamically formed hydrous zirconium (IV) oxide-polyelectrolyte membranes. III: Poly(acrylic acid) and substituted poly(acrylic acid) homo, co and terpolymer membranes

International Nuclear Information System (INIS)

Van Reenen, A.J.; Sanderson, R.D.

1989-01-01

A series of acrylic acid and substituted acrylic acid homo, co and terpolymers was synthesised. These polymers were used as polyelectrolytes in dynamically formed hydrous zirconium (iv) oxide-polyelectrolyte membranes. Substitution of the acrylic acid α-hydrogen was done to increase the number of carboxylic acid groups per monomer unit and to change the acid strength of acrylic acid carboxylic acid group. None of these changes improved the salt rejection of these membranes over that of commercially used poly(acrylic acid). Improvement in rejection was found when a hydrophobic comonomer, vinyl acetate, was used in conjunction with acrylic acid in a copolymer dynamic membrane. 16 refs., 6 figs., 1 tab

Anaerobic biotransformation of roxarsone and related N-substituted phenylarsonic acids

Science.gov (United States)

Cortinas, I.; Field, J.A.; Kopplin, M.; Garbarino, J.R.; Gandolfi, A.J.; Sierra-Alvarez, R.

2006-01-01

Large quantities of arsenic are introduced into the environment through land application of poultry litter containing the organoarsenical feed additive roxarsone (3-nitro-4-hydroxyphenylarsonic acid). The objective of this study was to evaluate the bioconversion of roxarsone and related N-substituted phenylarsonic acid derivatives under anaerobic conditions. The results demonstrate that roxarsone is rapidly transformed in the absence of oxygen to the corresponding aromatic amine, 4-hydroxy-3-aminophenylarsonic acid (HAPA). The formation of HAPA is attributable to the facile reduction of the nitro group. Electron-donating substrates, such as hydrogen gas, glucose, and lactate, stimulated the rate of nitro group reduction, indicating a microbial role. During long-term incubations, HAPA and the closely related 4-aminophenylarsonic acid (4-APA) were slowly biologically eliminated by up to 99% under methanogenic and sulfate-reducing conditions, whereas little or no removal occurred in heat-killed inoculum controls. Arsenite and, to a lesser extent, arsenate were observed as products of the degradation. Freely soluble forms of the inorganic arsenical species accounted for 19-28% of the amino-substituted phenylarsonic acids removed. This constitutes the first report of a biologically catalyzed rupture of the phenylarsonic group under anaerobic conditions. ?? 2006 American Chemical Society.

Feature-Based Classification of Amino Acid Substitutions outside Conserved Functional Protein Domains

Directory of Open Access Journals (Sweden)

Branislava Gemovic

2013-01-01

Full Text Available There are more than 500 amino acid substitutions in each human genome, and bioinformatics tools irreplaceably contribute to determination of their functional effects. We have developed feature-based algorithm for the detection of mutations outside conserved functional domains (CFDs and compared its classification efficacy with the most commonly used phylogeny-based tools, PolyPhen-2 and SIFT. The new algorithm is based on the informational spectrum method (ISM, a feature-based technique, and statistical analysis. Our dataset contained neutral polymorphisms and mutations associated with myeloid malignancies from epigenetic regulators ASXL1, DNMT3A, EZH2, and TET2. PolyPhen-2 and SIFT had significantly lower accuracies in predicting the effects of amino acid substitutions outside CFDs than expected, with especially low sensitivity. On the other hand, only ISM algorithm showed statistically significant classification of these sequences. It outperformed PolyPhen-2 and SIFT by 15% and 13%, respectively. These results suggest that feature-based methods, like ISM, are more suitable for the classification of amino acid substitutions outside CFDs than phylogeny-based tools.

Structural consequences of amino acid substitutions causing Tay-Sachs disease.

Science.gov (United States)

Ohno, Kazuki; Saito, Seiji; Sugawara, Kanako; Sakuraba, Hitoshi

2008-08-01

To determine the structural changes in the alpha-subunit of beta-hexosaminidase due to amino acid substitutions causing Tay-Sachs disease, we built structural models of mutant alpha-subunits resulting from 33 missense mutations (24 infantile and 9 late-onset), and analyzed the influence of each amino acid replacement on the structure by calculating the number of atoms affected and determining the solvent-accessible surface area of the corresponding amino acid residue in the wild-type alpha-subunit. In the infantile Tay-Sachs group, the number of atoms influenced by a mutation was generally larger than that in the late-onset Tay-Sachs group in both the main chain and the side chain, and residues associated with the mutations found in the infantile Tay-Sachs group tended to be less solvent-accessible than those in the late-onset Tay-Sachs group. Furthermore, color imaging determined the distribution and degree of the structural changes caused by representative amino acid substitutions, and that there were also differences between the infantile and late-onset Tay-Sachs disease groups. Structural study is useful for elucidating the basis of Tay-Sachs disease.

RESEARCH OF THE ADSORPTION OF ORGANIC ACIDS IN SUGARCANE BAGASSE ASH

Directory of Open Access Journals (Sweden)

Julio Omar Prieto García

2017-07-01

Full Text Available In this research a study of the adsorption of acetic, benzoic, butanoic, fumaric, maleic and succinic acids on sugarcane baggase ash is made. The adsorber material is characterized through physical criteria such as apparent and pictometric density, compressibility, porosity, superficial area and tortuosity. The sample has been examined by X-rays Diffraction, thermal analysis, IR-quality analysis. The isotherm for the sorption process is determined, where it is shown that the Freundlich model is adjusted to benzoic acid, the Langmuir and Toth model to acetic acid, Bunauer- Emmett- Teller (BET model to succinic acid and the butiric, maleic and fumaric acids are adjusted to Langmoir model. It is established that the first-order model is adjusted to the adsorption kinetics of the acetic and benzoic acids; while the rest of the acids are adjusted to a second-order model, in the case of the butanoic, succinic and maleic acids it is possible the occurrence of chemisorption processes.

Synthesis of hydroxylated and methoxylated polybrominated diphenyl ethers

Institute of Scientific and Technical Information of China (English)

ZHENG Ke-wen; GAO Li-ping; CAO Jie; YU Hai-wen; ZHANG Zhang

2009-01-01

Hydroxylated/methoxylated polybrominated diphenyl ethers (OH/MeO-PBDEs) are not only detected as natural products, but also regarded as metabolites formed from polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants in various materials. The aim of the present study was to synthesize authentic OH-PBDEs and MeO-PBDEs, as reference standards for environmental exploration. Twenty OH-PBDEs and their corresponding MeO-PBDEs containing three to six bromine atoms were synthesized via a trial of reactions including coupling, oxidation, bromination, methylation, etc. The products were characterized by GC-MS and 1H-NMR spectroscopy in the work. As results show, all compounds synthesized were up to 99% on purity and be reqarded as authentic standards for detecting the chemical pollutants in the emvironment.

OH-radical induced degradation of hydroxybenzoic- and hydroxycinnamic acids and formation of aromatic products-A gamma radiolysis study

Energy Technology Data Exchange (ETDEWEB)

Krimmel, Birgit; Swoboda, Friederike [University of Vienna, Department of Nutritional Sciences, Section Radiation Biology (Austria); Solar, Sonja, E-mail: sonja.solar@univie.ac.a [University of Vienna, Department of Nutritional Sciences, Section Radiation Biology (Austria); Reznicek, Gottfried [Department of Pharmacognosy, Althanstrasse 14, A-1090 Vienna (Austria)

2010-12-15

The OH-radical induced degradation of hydroxybenzoic acids (HBA), hydroxycinnamic acids (HCiA) and methoxylated derivatives, as well as of chlorogenic acid and rosmarinic acid was studied by gamma radiolysis in aerated aqueous solutions. Primary aromatic products resulting from an OH-radical attachment to the ring (hydroxylation), to the position occupied by the methoxyl group (replacement -OCH{sub 3} by -OH) as well as to the propenoic acid side chain of the cinnamic acids (benzaldehyde formations) were analysed by HPLC-UV and LC-ESI-MS. A comparison of the extent of these processes is given for 3,4-dihydroxybenzoic acid, vanillic acid, isovanillic acid, syringic acid, cinnamic acid, 4-hydroxycinnamic acid, caffeic acid, ferulic acid, isoferulic acid, chlorogenic acid, and rosmarinic acid. For all cinnamic acids and derivatives benzaldehydes were significant oxidation products. With the release of caffeic acid from chlorogenic acid the cleavage of a phenolic glycoside could be demonstrated. Reaction mechanisms are discussed.

Amino acid substitutions in inherited albumin variants from Amerindian and Japanese populations

International Nuclear Information System (INIS)

Takahashi, N.; Takahashi, Y.; Isobe, T.; Putnam, F.W.; Fujita, M.; Satoh, C.; Neel, J.V.

1987-01-01

The authors report an effort to determine the basis for the altered migration of seven inherited albumin variants detected by one-dimensional electrophoresis in population surveys involving tribal Amerindians and Japanese children. An amino acid substitution has thus far been determined for four of the variants. The randomness in the albumin polypeptide of these and the other sixteen independently ascertained amino acid substitutions of albumin and proalbumin thus far established was analyzed; the clustering of eight of these at two positions in the six-amino acid propeptide sequence seems noteworthy. By comparison with other proteins studied by electrophoresis, albumin exhibits average variability. It is a paradox that individuals who, for genetic reasons, lack albumin exhibit no obvious ill effects; yet, electrophoretic variants of albumin are no more numerous than are variants of proteins, the absence of which results in severe disease

New 3,4-diaminobenzoic acid Schiff base compounds and their complexes: synthesis, characterization and thermodynamics.

Science.gov (United States)

Mohammadi, Khosro; Niad, Mahmood; Jafari, Tahereh

2014-03-25

Some new tetradentate Schiff base ligands (H3L) were prepared via condensation of 3,4-diaminobenzoic acid with 2-hydroxybenzaldehyde derivatives, such as 3,4-bis((E)-2,4-dihydroxybenzylideneamino)benzoic acid (H3L(1)), 3,4-bis((E)-2-hydroxy-3-methoxybenzylideneamino)benzoic acid (H3L(2)) and 3,4-bis((E)-5-bromo-2-hydroxybenzylideneamino)benzoic acid (H3L(4)). Additionally, a tetradentate Schiff base ligand 3,4-bis((E)-2-hydroxybenzylideneamino)benzoic acid (H3L(3)) and its complexes were synthesized. Their metal complexes of Co(II), Ni(II), Cu(II) and Zn(II) were prepared in good yields from the reaction of the ligands with the corresponding metal acetate. They were characterized based on IR, (1)H NMR, Mass spectroscopy and UV-Vis spectroscopy. Also, the formation constants of the complexes were measured by UV-Vis spectroscopic titration at constant ionic strength 0.1M (NaClO4), at 25 °C in dimethylformamide (DMF) as a solvent. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Emanation-thermal characteristics of Ba-salts of some aromatic acids in the temperature range between 298 and 373 K

Energy Technology Data Exchange (ETDEWEB)

Balek, V; Prachar, M [Ustav Jaderneho Vyzkumu, Rez (Czechoslovakia); Kroupa, J [Vyzkumny Ustav Syntetickych Pryskyric a Laku, Pardubice (Czechoslovakia)

1977-01-01

The paper presents the emanation-thermal characteristics of Ba salts of some monocarboxylic acids (phtalic, isophtalic and terephtalic) and dicarboxylic acids (benzoic, salicylic, 1,4-aminobenzoic, 1,2-Cl-benzoic and 1,2-I-benzoic). It is shown that the emanation thermal characteristics measured in the temperature range between 298 and 373 K are suitable for estimating diffusion properties of studied organic solids. An apparatus for determining emanation-thermal characteristics is proposed.

Role of a single amino acid substitution of VP3 H142D for increased acid resistance of foot-and-mouth disease virus serotype A.

Science.gov (United States)

Biswal, Jitendra K; Das, Biswajit; Sharma, Gaurav K; Khulape, Sagar A; Pattnaik, Bramhadev

2016-04-01

Foot-and-mouth disease virus (FMDV) particles lose infectivity due to their dissociation into pentamers at pH value below 6.5. After the uptake of FMDV by receptor-mediated endocytosis, the acid-dependent dissociation process is required for the release of FMDV genome inside endosomes. Nevertheless, dissociation of FMDV particles in mildly acidic conditions renders the inactivated FMD vaccine less effective. To improve the acid stability of inactivated FMD vaccine during the manufacturing process, a serotype A IND 40/2000 (in-use vaccine strain) mutant with increased resistance to acid inactivation was generated through reverse genetics approach. Based upon the earlier reports, the crucial amino acid residue, H142 of VP3 capsid protein was substituted separately to various amino acid residues Arg (R), Phe (F), Ala (A), and Asp (D) on the full-genome length cDNA clone. While the H142 → R or H142 → F or H142 → A substitutions resulted in non-infectious FMDV, H142 → D mutation on VP3 protein (H3142D) resulted in the generation of mutant virus with enhanced resistance to acid-induced inactivation. In addition, H3142D substitution did not alter the replication ability and antigenicity of mutant as compared to the parental virus. However, the virus competition experiments revealed that the H3142D substitution conferred a loss of fitness for the mutant virus. Results from this study demonstrate that the H3142D substitution is the molecular determinant of acid-resistant phenotype in FMDV serotype A.

Synthesis, characterization and biological studies of 2-(4-nitrophenylamino-carbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

International Nuclear Information System (INIS)

Imran, M; Nazir, S.; Latif, S.; Mahmood, Z.

2010-01-01

Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2-(4-Nitrophenyl aminocarbonyl)benzoic acid were synthesized and characterized on the basis of physical, analytical and spectroscopic data. The ligands, as well as its metal complexes were checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis, Escherichia coli, Pseudomonas aeuroginosa, and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. Disc diffusion method and Tube diffusion test were used for antibacterial and antifungal activities, respectively. The synthesized complexes only show significant antifungal activity but inactive for antibacterial, however, in general, the metal complexes were found to be more active against antimicrobial activities as compared to their un complexed ligand. (author)

Low-methoxyl lemon pectin attenuates inflammatory responses and improves intestinal barrier integrity in caerulein-induced experimental acute pancreatitis

NARCIS (Netherlands)

Sun, Yajun; He, Yue; Wang, Fei; Zhang, Hao; de Vos, Paul; Sun, Jia

Scope: Acute pancreatitis (AP) is a common clinical acute abdominal disease. The intestinal injury associated with AP will aggravate the condition retroactively. This study investigates whether the low-methoxyl pectin (LMP) isolated from lemon could attenuate AP and associated intestinal injury.

Improving the thermal stability and electrical parameters of a liquid crystalline material 4-n-(nonyloxy) benzoic acid by using Li ion beam irradiation

Science.gov (United States)

Kumar, Satendra; Verma, Rohit; Dwivedi, Aanchal; Dhar, R.; Tripathi, Ambuj

2018-05-01

Li ion beam irradiation studies on a liquid crystalline material 4-n-(nonyloxy) benzoic acid (NOBA) have been carried out. The material has phase sequence of I-N-SmC-Cr. Thermodynamic studies demonstrate that an irradiation fluence of 1×1013 ions-cm-2 results in the increased thermal stability of the smectic C (SmC) phase of the material. Dielectric measurements illustrate that the transverse component of the dielectric permittivity and hence the dielectric anisotropy of the material in the nematic (N) and SmC phases are increased as compared to those of the pure material due to irradiation. UV-Visible spectrum of the irradiated material shows an additional peak along with the peak of the pure material. The observed change in the thermodynamic and electrical parameters is attributed to the conversion of some of the dimers of NOBA to monomers of NOBA due to irradiation.

Aspergillus fumigatus CY018, an endophytic fungus in Cynodon dactylon as a versatile producer of new and bioactive metabolites.

Science.gov (United States)

Liu, J Y; Song, Y C; Zhang, Z; Wang, L; Guo, Z J; Zou, W X; Tan, R X

2004-11-09

Aspergillus fumigatus CY018 was recognized as an endophytic fungus for the first time in the leaf of Cynodon dactylon. By bioassay-guided fractionation, the EtOAc extract of a solid-matrix steady culture of this fungus afforded two new metabolites, named asperfumoid (1) and asperfumin (2), together with six known bioactive compounds including monomethylsulochrin, fumigaclavine C, fumitremorgin C, physcion, helvolic acid and 5alpha,8alpha-epidioxy-ergosta-6,22-diene-3beta-ol as well as other four known compounds ergosta-4,22-diene-3beta-ol, ergosterol, cyclo(Ala-Leu) and cyclo(Ala-Ile). Through detailed spectroscopic analyses including HRESI-MS, homo- and hetero-nuclear correlation NMR experiments (HMQC, COSY, NOESY and HMBC), the structures of asperfumoid and asperfumin were established to be spiro-(3-hydroxyl-2,6-dimethoxyl-2,5-diene-4-cyclohexone-(1,3')-5'-methoxyl-7'-methyl-(1'H, 2'H, 4'H)-quinoline-2',4'-dione) and 5-hydroxyl-2-(6-hydroxyl-2-methoxyl-4-methylbenzoyl)-3,6-dimethoxyl-benzoic methyl ester, respectively. All of the 12 isolates were subjected to in vitro bioactive assays against three human pathogenic fungi Candida albicans, Tricophyton rubrum and Aspergillus niger. As a result, asperfumoid, fumigaclavine C, fumitremorgin C, physcion and helvolic acid were shown to inhibit C. albicans with MICs of 75.0, 31.5, 62.5, 125.0 and 31.5 microg/mL, respectively.

Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes

Science.gov (United States)

Deshmukh, Dhananjay K.; Kawamura, Kimitaka; Lazaar, Manuel; Kunwar, Bhagawati; Boreddy, Suresh K. R.

2016-04-01

Size-segregated aerosols (nine stages from 11.3 µm in diameter) were collected at Cape Hedo, Okinawa, in spring 2008 and analyzed for water-soluble diacids (C2-C12), ω-oxoacids (ωC2-ωC9), pyruvic acid, benzoic acid, and α-dicarbonyls (C2-C3) as well as water-soluble organic carbon (WSOC), organic carbon (OC), and major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-, and MSA-). In all the size-segregated aerosols, oxalic acid (C2) was found to be the most abundant species, followed by malonic and succinic acids, whereas glyoxylic acid (ωC2) was the dominant oxoacid and glyoxal (Gly) was more abundant than methylglyoxal. Diacids (C2-C5), ωC2, and Gly as well as WSOC and OC peaked at fine mode (0.65-1.1 µm) whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at coarse mode (3.3-4.7 µm). Sulfate and ammonium were enriched in fine mode, whereas sodium and chloride were in coarse mode. Strong correlations of C2-C5 diacids, ωC2 and Gly with sulfate were observed in fine mode (r = 0.86-0.99), indicating a commonality in their secondary formation. Their significant correlations with liquid water content in fine mode (r = 0.82-0.95) further suggest an importance of the aqueous-phase production in Okinawa aerosols. They may also have been directly emitted from biomass burning in fine mode as supported by strong correlations with potassium (r = 0.85-0.96), which is a tracer of biomass burning. Bimodal size distributions of longer-chain diacid (C9) and oxoacid (ωC9) with a major peak in the coarse mode suggest that they were emitted from the sea surface microlayers and/or produced by heterogeneous oxidation of biogenic unsaturated fatty acids on sea salt particles.

Amino acid-substituted gemini surfactant-based nanoparticles as safe and versatile gene delivery agents.

Science.gov (United States)

Singh, Jagbir; Yang, Peng; Michel, Deborah; Verrall, Ronald E; Foldvari, Marianna; Badea, Ildiko

2011-05-01

Gene based therapy represents an important advance in the treatment of diseases that heretofore have had either no treatment or cure. To capitalize on the true potential of gene therapy, there is a need to develop better delivery systems that can protect these therapeutic biomolecules and deliver them safely to the target sites. Recently, we have designed and developed a series of novel amino acid-substituted gemini surfactants with the general chemical formula C(12)H(25) (CH(3))(2)N(+)-(CH(2))(3)-N(AA)-(CH(2))(3)-N(+) (CH(3))(2)-C(12)H(25) (AA= glycine, lysine, glycyl-lysine and, lysyl-lysine). These compounds were synthesized and tested in rabbit epithelial cells using a model plasmid and a helper lipid. Plasmid/gemini/lipid (P/G/L) nanoparticles formulated using these novel compounds achieved higher gene expression than the nanoparticles containing the parent unsubstituted compound. In this study, we evaluated the cytotoxicity of P/G/L nanoparticles and explored the relationship between transfection efficiency/toxicity and their physicochemical characteristics (such as size, binding properties, etc.). An overall low toxicity is observed for all complexes with no significant difference among substituted and unsubstituted compounds. An interesting result revealed by the dye exclusion assay suggests a more balanced protection of the DNA by the glycine and glycyl-lysine substituted compounds. Thus, the higher transfection efficiency is attributed to the greater biocompatibility and flexibility of the amino acid/peptide-substituted gemini surfactants and demonstrates the feasibility of using amino acid-substituted gemini surfactants as gene carriers for the treatment of diseases affecting epithelial tissue.

FTIR spectroscopic study on the Hofmann -Td- type clathrates: Ni(benzoic acid)2M(CN)4.aniline (M=Zn, Cd, Hg)

International Nuclear Information System (INIS)

Kesan, G.; Kartal, Z.

2010-01-01

The Hofmann-Td-type clathrates formulated as Ni(L) 2 M(CN) 4 .nG where L is a bidentate or a pair of unidentate ligand molecule, M is Zn, Cd or Hg, G is a guest molecule and n is the number of guest molecule. The host lattice of the Hofmann-Td-type clathrates is formed from endless chains of -Ni-L-L-Ni-L-L-Ni- and M(CN) 4 ions arranged between the consecutive crossing -Ni-L-L-Ni-L-L-Ni- chains with the O-ends bound to the Ni metal atoms. These polymeric layers are held in parallel by Van der Walls interaction between ligand molecules. This structure provides α-type cavity. In this study, Ni(Benzoic Acid ) 2M(CN) 4 .Aniline (M = Zn, Cd, Hg) is obtained for the first time by means of chemical methods in powder form and their infrared spectra are reported in range of (4000-400) cm - 1. The spectral data suggest that the new clathrates are similar in structure to the Hofmann-type clathrates.

Synthesis, kinetic mechanism and docking studies of vanillin derivatives as inhibitors of mushroom tyrosinase.

Science.gov (United States)

Ashraf, Zaman; Rafiq, Muhammad; Seo, Sung-Yum; Babar, Mustafeez Mujtaba; Zaidi, Najam-us-Sahar Sadaf

2015-09-01

The purpose of the present study was to discover the extent of contribution to antityrosinase activity by adding hydroxy substituted benzoic acid, cinnamic acid and piperazine residues to vanillin. The study showed the transformation of vanillin into esters as shown in (4a-4d), (6a-6b), and (8a-8b). In addition, the relationship between structures of these esters and their mushroom tyrosinase inhibitory activity was explored. The kinetics of inhibition on mushroom tyrosinase by these esters was also investigated. It was found that hydroxyl substituted benzoic acid derivatives were weak inhibitors; however hydroxy or chloro substituted cinnamic acid and piperazine substituted derivatives were able to induce significant tyrosinase inhibition. The mushroom tyrosinase (PDBID 2ZWE) was docked with synthesized vanillin derivatives and their calculated binding energies were compared with experimental IC50 values which provided positive correlation. The most potent derivative 2-(4-formyl-2-methoxyphenoxy)-2-oxoethyl (2E)-3-(4-hydroxyphenyl)prop-2-enoate (6a) possesses hydroxy substituted cinnamic acid scaffold having IC50 value 16.13 μM with binding energy of -7.2 kcal/mol. The tyrosinase inhibitory activity of (6a) is comparable with standard kojic acid. Kinetic analysis indicated that compound 6a was mixed-type tyrosinase inhibitor with inhibition constant values Ki (13 μM) and Ki' (53 μM) and formed reversible enzyme inhibitor complex. The active vanillin analog (6a) was devoid of toxic effects as shown in cytotoxic studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of isotopic substitution for studing thermal decomposition of silico-12-tungstic acid

International Nuclear Information System (INIS)

Khakhinov, V.V.; Pinchuk, I.N.; Tumurova, L.V.; Mokhosoev, M.V.

1987-01-01

Using the methods of thermal analysis and isotopic substitution, the mechanism of dehydration and decomposition of silico-12-tungstic acid hydrate is studied. It is found that H-D exchange leads to elevation of temperature of heteropoly acid decomposition. The observed isotopic effect shows that proton transfer is the limiting stage of the reaction

Transformation of hydroxylated and methoxylated 2,2',4,4',5-brominated diphenyl ether (BDE-99) in plants

Institute of Scientific and Technical Information of China (English)

Lili Pan; Jianteng Sun; Xiaodan Wu; Zi Wei; Lizhong Zhu

2016-01-01

The occurrence and fate of hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have received significant attention.However,there is limited information on the metabolism relationship between OH-pentaBDEs and MeO-pentaBDEs that were frequently detected with relatively high concentrations in the environment.In this study,the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice,wheat,and soybean plants.All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites,while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean.The conversion of parent compounds was the highest in soybean,followed by wheat and rice.Transformation products were found mainly in the roots,with few metabolites being translocated to the shoots and solution after exposure.The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.

Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea

Science.gov (United States)

Przybyłek, Maciej; Ziółkowska, Dorota; Kobierski, Mirosław; Mroczyńska, Karina; Cysewski, Piotr

2016-01-01

The possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first stage cocrystal screening. Additionally, the application of orientation effect to cocrystal screening simplifies the analysis due to damping of majority of diffraction signals coming from coformers. During validation phase the proposed approach successfully reproduced both positive cases of cocrystallization (urea:salicylic acid and urea:4-hydroxy benzoic acid) as well as pairs of co-formers immiscible in the solid state (urea:benzoic acid and urea:acetylsalicylic acids). Based on validated approach new cocrystals of urea were identified in complexes with 3-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid. In all cases formation of multicomponent crystal phase was confirmed by the appearance of new reflexes on the diffraction patterns and FTIR absorption band shifts of O-H and N-H groups.

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. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Thermodynamics of axial substitution and kinetics of reactions with amino acids for the paddlewheel complex tetrakis(acetato)chloridodiruthenium(II,III).

Science.gov (United States)

Santos, Rodrigo L S R; van Eldik, Rudi; de Oliveira Silva, Denise

2012-06-18

The known paddlewheel, tetrakis(acetato)chloridodiruthenium(II,III), offers a versatile synthetic route to a novel class of antitumor diruthenium(II,III) metallo drugs, where the equatorial ligands are nonsteroidal anti-inflammatory carboxylates. This complex was studied here as a soluble starting prototype model for antitumor analogues to elucidate the reactivity of the [Ru(2)(CH(3)COO)(4)](+) framework. Thermodynamic studies on equilibration reactions for axial substitution of water by chloride and kinetic studies on reactions of the diaqua complexes with the amino acids glycine, cysteine, histidine, and tryptophan were performed. The standard thermodynamic reaction parameters ΔH°, ΔS°, and ΔV° were determined and showed that both of the sequential axial substitution reactions are enthalpy driven. Kinetic rate laws and rate constants were determined for the axial substitution reactions of coordinated water by the amino acids that gave the corresponding aqua(amino acid)-Ru(2) substituted species. The results revealed that the [Ru(2)(CH(3)COO)(4)](+) paddlewheel framework remained stable during the axial ligand substitution reactions and was also mostly preserved in the presence of the amino acids.

Pervasive adaptive protein evolution apparent in diversity patterns around amino acid substitutions in Drosophila simulans.

Directory of Open Access Journals (Sweden)

Shmuel Sattath

2011-02-01

Full Text Available In Drosophila, multiple lines of evidence converge in suggesting that beneficial substitutions to the genome may be common. All suffer from confounding factors, however, such that the interpretation of the evidence-in particular, conclusions about the rate and strength of beneficial substitutions-remains tentative. Here, we use genome-wide polymorphism data in D. simulans and sequenced genomes of its close relatives to construct a readily interpretable characterization of the effects of positive selection: the shape of average neutral diversity around amino acid substitutions. As expected under recurrent selective sweeps, we find a trough in diversity levels around amino acid but not around synonymous substitutions, a distinctive pattern that is not expected under alternative models. This characterization is richer than previous approaches, which relied on limited summaries of the data (e.g., the slope of a scatter plot, and relates to underlying selection parameters in a straightforward way, allowing us to make more reliable inferences about the prevalence and strength of adaptation. Specifically, we develop a coalescent-based model for the shape of the entire curve and use it to infer adaptive parameters by maximum likelihood. Our inference suggests that ∼13% of amino acid substitutions cause selective sweeps. Interestingly, it reveals two classes of beneficial fixations: a minority (approximately 3% that appears to have had large selective effects and accounts for most of the reduction in diversity, and the remaining 10%, which seem to have had very weak selective effects. These estimates therefore help to reconcile the apparent conflict among previously published estimates of the strength of selection. More generally, our findings provide unequivocal evidence for strongly beneficial substitutions in Drosophila and illustrate how the rapidly accumulating genome-wide data can be leveraged to address enduring questions about the genetic basis

Pervasive adaptive protein evolution apparent in diversity patterns around amino acid substitutions in Drosophila simulans.

Science.gov (United States)

Sattath, Shmuel; Elyashiv, Eyal; Kolodny, Oren; Rinott, Yosef; Sella, Guy

2011-02-10

In Drosophila, multiple lines of evidence converge in suggesting that beneficial substitutions to the genome may be common. All suffer from confounding factors, however, such that the interpretation of the evidence-in particular, conclusions about the rate and strength of beneficial substitutions-remains tentative. Here, we use genome-wide polymorphism data in D. simulans and sequenced genomes of its close relatives to construct a readily interpretable characterization of the effects of positive selection: the shape of average neutral diversity around amino acid substitutions. As expected under recurrent selective sweeps, we find a trough in diversity levels around amino acid but not around synonymous substitutions, a distinctive pattern that is not expected under alternative models. This characterization is richer than previous approaches, which relied on limited summaries of the data (e.g., the slope of a scatter plot), and relates to underlying selection parameters in a straightforward way, allowing us to make more reliable inferences about the prevalence and strength of adaptation. Specifically, we develop a coalescent-based model for the shape of the entire curve and use it to infer adaptive parameters by maximum likelihood. Our inference suggests that ∼13% of amino acid substitutions cause selective sweeps. Interestingly, it reveals two classes of beneficial fixations: a minority (approximately 3%) that appears to have had large selective effects and accounts for most of the reduction in diversity, and the remaining 10%, which seem to have had very weak selective effects. These estimates therefore help to reconcile the apparent conflict among previously published estimates of the strength of selection. More generally, our findings provide unequivocal evidence for strongly beneficial substitutions in Drosophila and illustrate how the rapidly accumulating genome-wide data can be leveraged to address enduring questions about the genetic basis of adaptation.

Synthesis， Characterization and Inhibition Effects of Vanadium Substituted Dawson-type Heteropoly Acids(Mo， P)

Institute of Scientific and Technical Information of China (English)

YIN Yan-bing; YANG Yu-lin; FAN Rui-qing; ZHU Yang-qing; SUN Ji-ru

2011-01-01

Four new vanadium substituted Dawson-type heteropoly acids H7[P2Mo17VO62]·39H2O(1),H8[P2Mo16V2O62]·41H2O(2), H9[P2Mo15V3O62]·51H2O(3) and H8[P2Mo14V4O62H2]·45H2O(4) were prepared respectively. Their structures were determined by IR and ICP. The inhibition effects of vanadium substituted Dawson-type heteropoly acids(Mo, P) on free radical polymerization of methyl methacrylate(MMA) were investigated by dilatometry. The results show that the rate of the polymerization of MMA decreases and the inhibition effects of the four heteropoly acids reach the inhibitor performance of hydroquinone at a certain ratio.

Single amino acid substitution in important hemoglobinopathies does not disturb molecular function and biological process

Directory of Open Access Journals (Sweden)

Viroj Wiwanitkit

2008-06-01

Full Text Available Viroj WiwanitkitDepartment of Laboratory Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandAbstract: Hemoglobin is an important protein found in the red cells of many animals. In humans, the hemoglobin is mainly distributed in the red blood cell. Single amino acid substitution is the main pathogenesis of most hemoglobin disorders. Here, the author used a new gene ontology technology to predict the molecular function and biological process of four important hemoglobin disorders with single substitution. The four studied important abnormal hemoglobins (Hb with single substitution included Hb S, Hb E, Hb C, and Hb J-Baltimore. Using the GoFigure server, the molecular function and biological process in normal and abnormal hemoglobins was predicted. Compared with normal hemoglobin, all studied abnormal hemoglobins had the same function and biological process. This indicated that the overall function of oxygen transportation is not disturbed in the studied hemoglobin disorders. Clinical findings of oxygen depletion in abnormal hemoglobin should therefore be due to the other processes rather than genomics, proteomics, and expression levels.Keywords: hemoglobin, amino acid, substitution, function

Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

International Nuclear Information System (INIS)

Jiang Xianrong; Yuan Hongyan; Feng Yunlong

2012-01-01

Five Zn(II) and Cd(II) coordination polymers, [Zn 2 (BOABA)(bpp)(OH)]·0.5H 2 O (1), [Cd 3 (BOABA) 2 (bpp) 2 (H 2 O) 6 ]·2H 2 O (2), [Cd 3 (BOABA) 2 (2,2′-bipy) 3 (H 2 O) 4 ]·5.5H 2 O (3), [CdNa(BOABA)(H 2 O)] 2 ·H 2 O (4) and [Cd 2 (BOABA)(bimb)Cl(H 2 O) 2 ]·H 2 O (5) (H 3 BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2′-bipy=2,2′-bipyridine, bimb=1,4-bis(imidazol-1′-yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2′-bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {Cd 2 Na 2 } clusters and BOABA 3– ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {Cd 4 Cl 2 } clusters and BOABA 3– ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature. - Graphical abstract: Five new d 10 metal(II) coordination polymers based on H 3 BOABA ligand were obtained and characterized. They display different topological structures and luminescent properties. Highlights: ► Five d 10 metal(II) polymers based on 3,5-bis-oxyacetate-benzoic acid were obtained. ► The polymers were structurally characterized by single-crystal X-ray diffraction. ► Polymers 1–5 display different topological structures. ► They show strong fluorescent emission bands in the solid state.

"Customizable" units in di- and tripeptides: selective conversion into substituted dehydroamino acids.

Science.gov (United States)

Saavedra, Carlos J; Boto, Alicia; Hernández, Rosendo

2012-07-20

The selective conversion of serine or threonine units of di- and tripeptides into substituted dehydroamino acids is reported. Thus, these common α-amino acids undergo a scission-phosphorylation process to give α-amino phosphonate residues. A Horner-Wadsworth-Emmons reaction with aldehydes or ketones follows to afford the final products with excellent Z-stereoselectivity (Z:E > 98:2). In this way, a single peptide precursor can selectively be transformed into a variety of derivatives.

Acid-Base Equilibria of Some N-Substituted Thiophene-2-Carboxamidoximes in Non-Aqueous Media

OpenAIRE

DÜRÜST, Nedime

2002-01-01

The protonation constants of the amino nitrogens of some N-substituted thiophene-2-carboxamidoximes have been determined in acetic acid by means of potentiometric titration with perchloric acid. pKa values of the title compounds were interpreted on the basis of structural effects due to the substituents and the main skeleton.

Synthesis, Antifungal Evaluation and In Silico Study of N-(4-Halobenzyl)amides.

Science.gov (United States)

Montes, Ricardo Carneiro; Perez, Ana Luiza A L; Medeiros, Cássio Ilan S; Araújo, Marianna Oliveira de; Lima, Edeltrudes de Oliveira; Scotti, Marcus Tullius; Sousa, Damião Pergentino de

2016-12-13

A collection of 32 structurally related N -(4-halobenzyl)amides were synthesized from cinnamic and benzoic acids through coupling reactions with 4-halobenzylamines, using (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP) as a coupling agent. The compounds were identified by spectroscopic methods such as infrared, ¹H- and 13 C- Nuclear Magnetic Resonance (NMR) and high-resolution mass spectrometry. The compounds were then submitted to antimicrobial tests by the minimum inhibitory concentration method (MIC) and nystatin was used as a control in the antifungal assays. The purpose of the tests was to evaluate the influence of structural changes in the cinnamic and benzoic acid substructures on the inhibitory activity against strains of Candida albicans , Candida tropicalis , and Candida krusei . A quantitative structure-activity relationship (QSAR) study with KNIME v. 3.1.0 and Volsurf v. 1.0.7 softwares were realized, showing that descriptors DRDRDR, DRDRAC, L4LgS, IW4 and DD2 influence the antifungal activity of the haloamides. In general, 10 benzamides revealed fungal sensitivity, especially a vanillic amide which enjoyed the lowest MIC. The results demonstrate that a hydroxyl group in the para position, and a methoxyl at the meta position enhance antifungal activity for the amide skeletal structure. In addition, the double bond as a spacer group appears to be important for the activity of amide structures.

D-amino acid substitution enhances the stability of antimicrobial peptide polybia-CP.

Science.gov (United States)

Jia, Fengjing; Wang, Jiayi; Peng, Jinxiu; Zhao, Ping; Kong, Ziqing; Wang, Kairong; Yan, Wenjin; Wang, Rui

2017-10-01

With the increasing emergence of resistant microbes toward conventional antimicrobial agents, there is an urgent need for the development of antimicrobial agents with novel action mode. Antimicrobial peptides (AMPs) are believed to be one kind of ideal alternatives. However, AMPs can be easily degraded by protease, which limited their therapeutic use. In the present study, D-amino acid substitution strategy was employed to enhance the stability of polybia-CP. We investigated the stability of peptides against the degradation of trypsin and chymotrypsin by determining the antimicrobial activity or determining the HPLC profile of peptides after incubation with proteases. Our results showed that both the all D-amino acid derivative (D-CP) and partial D-lysine substitution derivative (D-lys-CP) have an improved stability against trypsin and chymotrypsin. Although D-CP takes left-hand α-helical conformation and D-lys-CP loses some α-helical content, both of the D-amino acid-substituted derivatives maintain their parental peptides' membrane active action mode. In addition, D-lys-CP showed a slight weaker antimicrobial activity than polybia-CP, but the hemolytic activity decreased greatly. These results suggest that D-CP and D-lys-CP can offer strategy to improve the property of AMPs and may be leading compounds for the development of novel antimicrobial agents. © The Author 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Synthesis of substituted 1,3-diesters of glycerol using wittig chemistry.

Science.gov (United States)

Lowe, Henry I C; Toyang, Ngeh J; Watson, Charah T; Bryant, Joseph

2014-05-01

1,3-di-O-Cinnamoyl-glycerol is a natural compound isolated from a Jamaican medicinal plant commonly referred to as Ball moss (Tillandsia recurvata). The synthesis of this compound was achieved via a Wittig chemistry process. The synthetic approach started with acylation of a di-protected glycerol with cinnamoyl chloride, deprotection of the glycerol moiety, reaction of the primary alcohol with bromo acetylbromide followed by treatment with triphenyl phosphine to give the corresponding phosphonium bromide. The phosphonium bromide was then converted in situ to the Wittig reagent which is the basis for a novel route to 1,3-di-O-cinnamoyl glycerol. Four analogs were also synthesized, three of which are new and are being reported in this article for the first time. The new compounds include 3-(3,4-diemthoxy-phenyl)-acrylic acid 2-hydroxy-3-(3-ptolyl-acryloyloxy)-propyl ester (3), 2-acetoxy-5-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop- 1-enyl)benzoic acid (4) and 4-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (5). The compounds showed no activity in our anticancer assay.

Five new prenylated p-hydroxybenzoic acid derivatives with antimicrobial and molluscicidal activity from Piper aduncum leaves.

Science.gov (United States)

Orjala, J; Erdelmeier, C A; Wright, A D; Rali, T; Sticher, O

1993-12-01

Five new prenylated benzoic acid derivatives, methyl 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxybenzoate (1), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-hydroxybenzoate (2), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (3), methyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (4), and 4-hydroxy-3-(3-methyl-2-butenyl)-5-(3-methyl-2-butenyl)-benzoic acid (5) were isolated from the dried leaves of Piper aduncum L. (Piperaceae). Together with the new metabolites, four known prenylated benzoic acid derivatives, 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (6), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (nervogenic acid, 7), methyl 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoate (8), and methyl 4-hydroxy-3-(3-methyl-2-butenyl)-benzoate (9) as well as, dillapiol (10), myristicin, and the three sesquiterpenes humulene, caryophyllene epoxide, and humulene epoxide were isolated. Compounds 7, 8, and 9 are reported as natural products for the first time. The structures of the isolates were elucidated by spectroscopic methods, mainly 1D-and 2D-NMR spectroscopy. Isolates 4-7, 9, and 10 were molluscicidal while 2, 5-7, and 9 displayed significant antibacterial activities.

ArrayPitope: Automated Analysis of Amino Acid Substitutions for Peptide Microarray-Based Antibody Epitope Mapping

DEFF Research Database (Denmark)

Hansen, Christian Skjødt; Østerbye, Thomas; Marcatili, Paolo

2017-01-01

and characterization of linear B cell epitopes. Using exhaustive amino acid substitution analysis of peptides originating from target antigens, these microarrays can be used to address the specificity of polyclonal antibodies raised against such antigens containing hundreds of epitopes. However, the interpretation....... The application takes as input quantitative peptide data of fully or partially substituted overlapping peptides from a given antigen sequence and identifies epitope residues (residues that are significantly affected by substitutions) and visualize the selectivity towards each residue by sequence logo plots...

Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes

Directory of Open Access Journals (Sweden)

D. K. Deshmukh

2016-04-01

Full Text Available Size-segregated aerosols (nine stages from < 0.43 to > 11.3 µm in diameter were collected at Cape Hedo, Okinawa, in spring 2008 and analyzed for water-soluble diacids (C2–C12, ω-oxoacids (ωC2–ωC9, pyruvic acid, benzoic acid, and α-dicarbonyls (C2–C3 as well as water-soluble organic carbon (WSOC, organic carbon (OC, and major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, SO42−, and MSA−. In all the size-segregated aerosols, oxalic acid (C2 was found to be the most abundant species, followed by malonic and succinic acids, whereas glyoxylic acid (ωC2 was the dominant oxoacid and glyoxal (Gly was more abundant than methylglyoxal. Diacids (C2–C5, ωC2, and Gly as well as WSOC and OC peaked at fine mode (0.65–1.1 µm whereas azelaic (C9 and 9-oxononanoic (ωC9 acids peaked at coarse mode (3.3–4.7 µm. Sulfate and ammonium were enriched in fine mode, whereas sodium and chloride were in coarse mode. Strong correlations of C2–C5 diacids, ωC2 and Gly with sulfate were observed in fine mode (r =  0.86–0.99, indicating a commonality in their secondary formation. Their significant correlations with liquid water content in fine mode (r =  0.82–0.95 further suggest an importance of the aqueous-phase production in Okinawa aerosols. They may also have been directly emitted from biomass burning in fine mode as supported by strong correlations with potassium (r =  0.85–0.96, which is a tracer of biomass burning. Bimodal size distributions of longer-chain diacid (C9 and oxoacid (ωC9 with a major peak in the coarse mode suggest that they were emitted from the sea surface microlayers and/or produced by heterogeneous oxidation of biogenic unsaturated fatty acids on sea salt particles.

Evaluating the efficacy of a structure-derived amino acid substitution matrix in detecting protein homologs by BLAST and PSI-BLAST

Directory of Open Access Journals (Sweden)

Nalin CW Goonesekere

2009-06-01

Full Text Available Nalin CW GoonesekereDepartment of Chemistry and Biochemistry, University of Northern iowa, Cedar Falls, IA, USAAbstract: The large numbers of protein sequences generated by whole genome sequencing projects require rapid and accurate methods of annotation. The detection of homology through computational sequence analysis is a powerful tool in determining the complex evolutionary and functional relationships that exist between proteins. Homology search algorithms employ amino acid substitution matrices to detect similarity between proteins sequences. The substitution matrices in common use today are constructed using sequences aligned without reference to protein structure. Here we present amino acid substitution matrices constructed from the alignment of a large number of protein domain structures from the structural classification of proteins (SCOP database. We show that when incorporated into the homology search algorithms BLAST and PSI-blaST, the structure-based substitution matrices enhance the efficacy of detecting remote homologs. Keywords: computational biology, protein homology, amino acid substitution matrix, protein structure

Correlation of aqueous solubility of salts of benzylamine with experimentally and theoretically derived parameters. A multivariate data analysis approach

DEFF Research Database (Denmark)

Parshad, Henrik; Frydenvang, Karla Andrea; Liljefors, Tommy

2002-01-01

Twenty two salts of benzylamine and p-substituted benzoic acids were prepared and characterized. The p-substituent was varied with regard to electronic, hydrophobic, and steric effects as well as hydrogen bonding potential. A multivariate data analysis was used to describe the relationship between...

Solid-phase synthesis of new saphenamycin analogues with antimicrobial activity

DEFF Research Database (Denmark)

Laursen, Jane B.; de Visser, P.C.; Nielsen, H.K.

2002-01-01

in parallel with a series of differently substituted benzoic acid derivatives. Treatment with TFA-CH2Cl2 (5:995) released the expected saphenamycin analogues into solution. These new analogues were purified, characterized and screened for antimicrobial activity against Bacillus subtilis and Proteus mirabilis...

Synthesis of specifically 2H-labeled reserpines, 3,4,5-trimethoxybenzoic acids, and syringic acid

International Nuclear Information System (INIS)

Roth, R.W.; Fischer, D.L.; Pachta, J.M.; Althaus, J.F.

1982-01-01

3,4,5-Trimethoxy- 2 H 9 -, 4-methoxy-3,5-dimethoxy- 2 H 6 , and 4-hydroxyl-3,5-dimethoxy- 2 H 6 -benzoic acids were prepared from n-propyl 3,4,5-trihydroxybenzoate (n-propyl gallate) by means of appropriate alkylation-hydrolysis sequences employing iodomethane- 2 H 3 or dimethyl- 2 H 6 -sulfate as the deuterium source. 4-Methoxy- 2 H 3 -3,5-dimethoxybenzoic acid was similarly prepared from ethyl 4-hydroxy-3,5-dimethoxybenzoate. The labeled trimethoxybenzoic acids were converted to the corresponding 2 H-labeled reserpines by condensation of the acid chlorides with methyl reserpate in pyridine according to the classical procedure. The labeled reserpine analog methyl 18-0-(4-hydroxy-3,5-dimethoxy- 2 H 6 )benzoyl reserpate was likewise prepared from 4-hydroxy-3,5-dimethoxy- 2 H 6 -benzoic acid via the intermediate methyl 18-0-(4-ethoxycarbonyloxy-3,5-dimethoxy- 2 H 6 -benzoyl)reserpate (syrosingopine- 2 H 6 ). The isotopic purity of each compound exceeded 99 atom percent 2 H. (author)

Experimental standard molar enthalpies of formation of some 4-alkoxybenzoic acids

International Nuclear Information System (INIS)

Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.; Maciel, Fabrice M.

2010-01-01

The present work is part of a research program on the energetics of the linear 4-n-alkoxybenzoic acids, aiming the study of the enthalpic effect of the introduction of an alkoxy chain in the position 4- of the benzoic acid ring. In this work, we present the results of the thermochemical research on 4-n-alkoxybenzoic acids with the alkoxy chain length n = 2, 4, and 8. The standard (p 0 =0.1MPa) molar enthalpy of formation of crystalline 4-ethoxybenzoic acid, 4-butoxybenzoic acid, and 4-(octyloxy)benzoic acid was measured, at T = 298.15 K, by static-bomb calorimetry. These values, combined with the values of standard molar enthalpies of sublimation, were used to derive the standard molar enthalpies of formation in the gaseous phase.

Metabolic labeling of sialic acids in tissue culture cell lines: methods to identify substituted and modified radioactive neuraminic acids

International Nuclear Information System (INIS)

Diaz, S.; Varki, A.

1985-01-01

The parent sialic acid N-acetylneuraminic acid can be modified or substituted in various ways, giving rise to a family of more than 25 compounds. The definitive identification of these compounds has previously required isolation of nanomole amounts for mass spectrometry or NMR. We have explored the possibility of using the known metabolic precursors of the sialic acids, particularly N-acetyl-[6-3H]mannosamine, to label and identify various forms of sialic acids in tissue culture cells. Firstly, we defined several variables that affect the labeling of sialic acids with N-acetyl-[6-3H]mannosamine. Secondly, we have devised a simple screening method to identify cell lines that synthesize substituted or modified sialic acids. We next demonstrate that it is possible to definitively identify the natures of the various labeled sialic acids without the use of mass spectrometry, even though they are present only in tracer amounts. The methods used include paper chromatography, analytical de-O-acetylation, periodate release of the 9-3H as [3H]formaldehyde (which is subsequently converted to a specific 3H-labeled chromophore), acylneuraminate pyruvate lyase treatment with identification of [3H]acylmannosamines, gas-liquid chromatography with radioactive detection, and two new high-pressure liquid chromatography methods utilizing the amine-adsorption:ion suppression and ion-pair principles. The use of an internal N-acetyl-[4-14C]neuraminic acid standard in each of these methods assures precision and accuracy. The combined use of these methods now allows the identification of radioactive tracer amounts of the various types of sialic acids in well-defined populations of tissue culture cells; it may also allow the identification of hitherto unknown forms of sialic acids

Rapid Access to Ortho-Alkylated Vinylarenes from Aromatic Acids by Dearomatization and Tandem Decarboxylative C-H Olefination/Rearomatization.

Science.gov (United States)

Tsai, Hung-Chang; Huang, Yen-Hsiang; Chou, Chih-Ming

2018-03-02

A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birch reduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C-H olefination followed by rearomatization to deliver ortho-alkylated vinylarene. Mechanistic studies suggest that a Pd/Ag bimetallic catalytic system is important in the tandem decarboxylative C-H olefination/rearomatization step.

Amino acid substitutions in genetic variants of human serum albumin and in sequences inferred from molecular cloning

International Nuclear Information System (INIS)

Takahashi, N.; Takahashi, Y.; Blumberg, B.S.; Putnam, F.W.

1987-01-01

The structural changes in four genetic variants of human serum albumin were analyzed by tandem high-pressure liquid chromatography (HPLC) of the tryptic peptides, HPLC mapping and isoelectric focusing of the CNBr fragments, and amino acid sequence analysis of the purified peptides. Lysine-372 of normal (common) albumin A was changed to glutamic acid both in albumin Naskapi, a widespread polymorphic variant of North American Indians, and in albumin Mersin found in Eti Turks. The two variants also exhibited anomalous migration in NaDodSO 4 /PAGE, which is attributed to a conformational change. The identity of albumins Naskapi and Mersin may have originated through descent from a common mid-Asiatic founder of the two migrating ethnic groups, or it may represent identical but independent mutations of the albumin gene. In albumin Adana, from Eti Turks, the substitution site was not identified but was localized to the region from positions 447 through 548. The substitution of aspartic acid-550 by glycine was found in albumin Mexico-2 from four individuals of the Pima tribe. Although only single-point substitutions have been found in these and in certain other genetic variants of human albumin, five differences exist in the amino acid sequences inferred from cDNA sequences by workers in three other laboratories. However, our results on albumin A and on 14 different genetic variants accord with the amino acid sequence of albumin deduced from the genomic sequence. The apparent amino acid substitutions inferred from comparison of individual cDNA sequences probably reflect artifacts in cloning or in cDNA sequence analysis rather than polymorphism of the coding sections of the albumin gene

The redox-Mannich reaction.

Science.gov (United States)

Chen, Weijie; Seidel, Daniel

2014-06-06

A complement to the classic three-component Mannich reaction, the redox-Mannich reaction, utilizes the same starting materials but incorporates an isomerization step that enables the facile preparation of ring-substituted β-amino ketones. Reactions occur under relatively mild conditions and are facilitated by benzoic acid.

Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

International Nuclear Information System (INIS)

Kolhe, Vishnu; Dwivedi, K.

1996-01-01

Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

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Michel Oelschlägel

2015-06-01

The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

"1H and "1"3C NMR Data on Hydroxy/methoxy Flavonoids and the Effects of Substituents on Chemical Shifts

International Nuclear Information System (INIS)

Yoon, Hyuk; Eom, Sung Lock; Hyun, Ji Ye; Jo, Geun Hyeong; Hwang, Do Seok; Lee, Sun Hee; Yong, Yeon Joong; Lee, Young Han; Lim, Yoong Ho; Park, Jun Cheol

2011-01-01

Polyphenols have recently been examined for such applications, and they are classified based on their carbon skeletons: phenolic acids with C6-C1 skeleton, hydrocinammates with C6-C_3 skeleton, stilbenes with C6-C2-C6 skeleton, and flavonoids with C6-C_3-C6 skeleton.2 Of these compounds, flavonoids are ubiquitously found in most plants. Since flavonoids belong to polyphenols, they have many hydroxy groups. From a bioavailability point of view, hydroxy groups prevent cell membrane transport, and hydroxyflavonoids can be metabolized by O-methyltransferases. However, methoxylated flavonoids may not have these problems. Hydroxylated or methoxylated flavonoids are found from natural sources. Nuclear magnetic resonance (NMR) spectroscopy is widely used to identify different compounds including hydroxylated or methoxylated flavonoids. Because the position and the number of substituted hydroxy or/and methoxy groups will change the "1H and "1"3C chemical shifts, it is important to understand these changes so that the structures of newly isolated hydroxy/methoxy-flavonoids can be easily identified

Preparation and characterization of PVDF separators for lithium ion cells using hydroxyl-terminated polybutadiene grafted methoxyl polyethylene glycol (HTPB-g-MPEG) as additive

Science.gov (United States)

Li, Hao; Niu, Dong-Hui; Zhou, Hui; Chao, Chun-Ying; Wu, Li-Jun; Han, Pei-Lin

2018-05-01

Hydroxyl-terminated polybutadiene grafted methoxyl polyethylene glycol (HTPB-g-MPEG) with different arm length were synthesized by grafting methoxyl poly(ethylene glycol)s (MPEGs, Mn = 350, 750, 1900 and 5000, respectively) to the hydroxyl-terminated polybutadiene (HTPB) molecule using isophorone diisocyanate (IPDI) as the coupling agent, and blended with PVDF to fabricate porous separators via phase inversion process. By measuring the composition, morphology and ion conductivity etc., the influence of HTPB-g-MPEG on structure and property of blend separators were discussed. Compared with pure PVDF separator with comparable porous structure, the adoption of HTPB-g-MPEG could not only decrease the crystallinity, but also enhance the stability of entrapped liquid electrolyte and corresponding ion conductivity. The cells assembled with such separators showed good initial discharge capacity and cyclic stability.

Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

Energy Technology Data Exchange (ETDEWEB)

Jiang Xianrong; Yuan Hongyan [Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China); Feng Yunlong, E-mail: sky37@zjnu.edu.cn [Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang 321004 (China)

2012-07-15

Five Zn(II) and Cd(II) coordination polymers, [Zn{sub 2}(BOABA)(bpp)(OH)]{center_dot}0.5H{sub 2}O (1), [Cd{sub 3}(BOABA){sub 2}(bpp){sub 2}(H{sub 2}O){sub 6}]{center_dot}2H{sub 2}O (2), [Cd{sub 3}(BOABA){sub 2}(2,2 Prime -bipy){sub 3}(H{sub 2}O){sub 4}]{center_dot}5.5H{sub 2}O (3), [CdNa(BOABA)(H{sub 2}O)]{sub 2}{center_dot}H{sub 2}O (4) and [Cd{sub 2}(BOABA)(bimb)Cl(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O (5) (H{sub 3}BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2 Prime -bipy=2,2 Prime -bipyridine, bimb=1,4-bis(imidazol-1 Prime -yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2 Prime -bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {l_brace}Cd{sub 2}Na{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {l_brace}Cd{sub 4}Cl{sub 2}{r_brace} clusters and BOABA{sup 3-} ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature. - Graphical abstract: Five new d{sup 10} metal(II) coordination polymers based on H{sub 3}BOABA ligand were obtained and characterized. They display different topological structures and luminescent properties. Highlights: Black-Right-Pointing-Pointer Five d{sup 10} metal(II) polymers based on 3,5-bis-oxyacetate-benzoic acid were obtained. Black-Right-Pointing-Pointer The polymers were structurally characterized by single-crystal X-ray diffraction. Black-Right-Pointing-Pointer Polymers 1-5 display different

Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids

KAUST Repository

Zhang, Jizhe

2014-01-01

Formic acid is an important commodity chemical as well as a promising medium for hydrogen storage and hydrogen production. In this paper, we report that formic acid can be produced through selective oxidation of glycerol, a low-cost by-product of biodiesel, by using vanadium-substituted phosphomolybdic acids as catalysts and molecular oxygen as the oxidant. Significantly, this catalytic system allows for high-concentration conversions and thus leads to exceptional efficiency. Specifically, 3.64 g of formic acid was produced from 10 g of glycerol/water (50/50 in weight) solution. © 2014 the Partner Organisations.

Potentiometric investigation of acid dissociation and anionic homoconjugation equilibria of substituted phenols in dimethyl sulfoxide[Substituted phenols; Acid-base equilibria; Dimethyl sulfoxide (DMSO); Potentiometry

Energy Technology Data Exchange (ETDEWEB)

Czaja, Malgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech. E-mail: lech@chemik.chem.univ.gda.pl

2003-10-01

Standard acidity constants, K{sub a}{sup DMSO} (HA), expressed as pK{sub a}{sup DMSO} (HA) values, and anionic homoconjugation constants, K{sup DMSO}{sub AHA{sup -}}, (in the form of lg K{sup DMSO}{sub AHA{sup -}} values) have been determined for 11 substituted phenol-phenolate systems a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO) with a potentiometric titration. A linear relationship has been determined between lg K{sup DMSO}{sub AHA{sup -}} and pK{sub a}{sup DMSO} (HA). The tendency towards anionic homoconjugation in these systems increases with increasing pK{sub a}{sup DMSO} (HA) that is with declining phenol acidity. The pK{sub a}{sup DMSO} (HA) are correlated with both pK{sub a}{sup W} (HA) water and other polar non-aqeous solvents.

Silica-Supported Polyphosphoric Acid in the Synthesis of 4-Substituted Tetrahydroisoquinoline Derivatives

Directory of Open Access Journals (Sweden)

Iliyan Ivanov

2013-02-01

Full Text Available We report herein an application of an α-amidoalkylation reaction, as an alternative efficient synthesis of 4-aryl- and 4-methyl-1,2,3,4-tetrahydroisoquinoline derivatives. The amides required for this purpose would result from reaction of aminoacetaldehyde dimethylacetal with different substituted benzenes in polyphosphoric acid, followed by acylation of the obtained amines with different acid chlorides or sulfochlorides. We compared the cyclisation step using conventional (milieu of acetic-trifluoracetic acid = 4:1 and solid supported reagents (SiO2/PPA, as recovered, regenerated and reused without loss of its activity catalyst. We found that in comparison to conventional methods, the yields of the reaction are greater and the reaction time is shorter.

Evaluating the efficacy of a structure-derived amino acid substitution matrix in detecting protein homologs by BLAST and PSI-BLAST.

Science.gov (United States)

Goonesekere, Nalin Cw

2009-01-01

The large numbers of protein sequences generated by whole genome sequencing projects require rapid and accurate methods of annotation. The detection of homology through computational sequence analysis is a powerful tool in determining the complex evolutionary and functional relationships that exist between proteins. Homology search algorithms employ amino acid substitution matrices to detect similarity between proteins sequences. The substitution matrices in common use today are constructed using sequences aligned without reference to protein structure. Here we present amino acid substitution matrices constructed from the alignment of a large number of protein domain structures from the structural classification of proteins (SCOP) database. We show that when incorporated into the homology search algorithms BLAST and PSI-blast, the structure-based substitution matrices enhance the efficacy of detecting remote homologs.

Effect of phenols and carboxylic acids on photochromism of 1-alkyl-2-(arylazo)imidazoles

International Nuclear Information System (INIS)

Gayen, Pallab; Sinha, Chittaranjan

2012-01-01

Light irradiated trans-to-cis isomerization of 1-alkyl-2-(arylazo)imidazole in the presence of phenol, catechol, benzoic acid and salicylic acid (called co-factors) has been studied in this work. The rate of trans→cis photoisomerization is decreased in the presence of co-factor in the medium and is dependent on the concentration of active quotient about photochrome. The decrease in rate follows catechol>benzoic acid>phenol>salicylic acid. This trend is due to the effects of dissociation ability of –O–H/–COOH, intermolecular association of the molecules etc. The reverse change, cis-to-trans, is very slow in light irradiation and has been carried out by a thermal process in the dark. The quantum yield of isomerization follows the same sequence of effects of co-factors. - Highlights: ► Photoisomerisation of 1-alkyl-2-(arylazo)imidazoles, trans-to-cis, is described in this work. ► The process is sensitive to the environment of the photochrome and the solution. ► The rate of photoisomerization decreases as catechol>benzoic acid>phenol>salicylic acid. ► The reverse isomerization, cis-to-trans is very slow with light and has been carried out with heat. ► The activation energy is less than these values when carried out in fresh solution only.

The use of orthologous sequences to predict the impact of amino acid substitutions on protein function.

Directory of Open Access Journals (Sweden)

Nicholas J Marini

2010-05-01

Full Text Available Computational predictions of the functional impact of genetic variation play a critical role in human genetics research. For nonsynonymous coding variants, most prediction algorithms make use of patterns of amino acid substitutions observed among homologous proteins at a given site. In particular, substitutions observed in orthologous proteins from other species are often assumed to be tolerated in the human protein as well. We examined this assumption by evaluating a panel of nonsynonymous mutants of a prototypical human enzyme, methylenetetrahydrofolate reductase (MTHFR, in a yeast cell-based functional assay. As expected, substitutions in human MTHFR at sites that are well-conserved across distant orthologs result in an impaired enzyme, while substitutions present in recently diverged sequences (including a 9-site mutant that "resurrects" the human-macaque ancestor result in a functional enzyme. We also interrogated 30 sites with varying degrees of conservation by creating substitutions in the human enzyme that are accepted in at least one ortholog of MTHFR. Quite surprisingly, most of these substitutions were deleterious to the human enzyme. The results suggest that selective constraints vary between phylogenetic lineages such that inclusion of distant orthologs to infer selective pressures on the human enzyme may be misleading. We propose that homologous proteins are best used to reconstruct ancestral sequences and infer amino acid conservation among only direct lineal ancestors of a particular protein. We show that such an "ancestral site preservation" measure outperforms other prediction methods, not only in our selected set for MTHFR, but also in an exhaustive set of E. coli LacI mutants.

Climate signal in d13C of wood lignin methoxyl groups from high-elevation alpine larch trees

Science.gov (United States)

Reichelmann, Dana; Greule, Markus; Treydte, Kerstin; Keppler, Frank; Esper, Jan

2015-04-01

Tree-rings of high alpine larch trees (Larix decidua) were investigated by a recently established method that measures d13C values of the wood lignin methoxyl groups (Greule et al. 2009). The resulting d13C time series were tested for their potential as a climate proxy. For this 37 larch trees were sampled at the tree line near Simplon Village (Southern Switzerland). They were analysed for their tree-ring width (TRW) and from five individuals d13C of the wood lignin methoxyl groups (d13Cmethoxyl) were measured at annual resolution from 1971-2009 and at pentadal resolution from 1747-2009. The d13Cmethoxyl chronologies were corrected for the anthropogenic change in atmospheric CO2 concentration and its decreasing d13C value. Further, the physiological response of the trees to these atmospheric changes was corrected using the flexible correction factor approach of Treydte et al. (2009), which minimise the residuals with the target climate data. This approach results in the highest so far reported correction factors of 0.032 - 0.036‰/ppmv CO2, which are explained by a low water-use efficiency of deciduous larch. The climate response of the new d13Cmethoxyl proxy shows a significant correlation of 0.75 for the annually and 0.87 for the pentadally resolved data with June to August temperatures. TRW shows also significant correlations with June to August temperatures, but they are lower than the correlations observed for the d13Cmethoxyl chronologies. These results indicate the potential of d13Cmethoxyl chronologies as a summer temperature proxy from high-elevation alpine trees with an even stronger signal than reported from earlier published tree-ring width and maximum latewood density temperature reconstructions. References: Greule, M., Mosandl, A., Hamilton, J.T.G., Keppler, F., 2009. A simple rapid method to precisely determine 13C/12C ratios of plant methoxyl groups. Rapid Communications in Mass Spectrometry, 23(11): 1710-1714. Treydte, K.S., Frank, D.C., Saurer, M

Isolation of gallic acid-producing microorganisms and their use in ...

African Journals Online (AJOL)

STORAGESEVER

al., 2005). Tannase is an industrially important enzyme ... The enzymatic product gallic acid (3,4,5-trihydroxy- benzoic ... also used in leather industry, in manufacturing gallic acid esters ..... the economics of a plant (Misro et al., 1997). At the 9 ...

Kinetic study of the substitution of [Tc(tu)6]3+ by polyaminocarboxylic acids

International Nuclear Information System (INIS)

Torres, J.; Gonalez, R.; Kremer, C.; Kremer, E.; Leon, A.

1997-01-01

Substitution route has been traditionally proposed for the synthesis of new Tc complexes. In particular, Tc(III) coordination compounds can be successfully prepared by substitution on [Tc(tu) 6 ] 3+ (tu = thiourea). In this substitution reaction, TcO 2 is a side product that should be minimized. The success of these synthetic procedures is based on controlling the reaction conditions in order that pure substitution could be faster enough compared to decomposition. In this work, the substitution of [Tc(tu) 6 ] 3+ by polycarboxylic acids (ethylenediaminetetraacetate (edta), diethylenetriaminepentaacetate (dtpa), N-tris(2-amino-ethyl)amin N', N', N '' , N '' , N ''' , N ''' -hexaacetate (ttaha) and 3-bromo-2,4,6-trimethylacetanilideiminodiacetate (mebrofenin)) is kinetically studied in order to obtain the best conditions for preparing Tc(III) complexes. As a general conclusion, substitution constants are strongly dependent on the pH. k obs values fall in the range 0.1-13 x 10 -2 M -1 s -1 , depending on the pH value and the temperature. No strong differences are found with different incoming ligands. For the four ligands (L), a straight line is obtained when plotting log k obs /([L m- ]) vs. pH. This is consistent with a rate constant k obs = {k 0 + Σk n [H + ] n /K n }[L m- ], where n represents the charge of the incoming ligand and m is the maximum value of n. (orig.)

Comparing the Effect of Diets Treated with Different Organic Acids ...

African Journals Online (AJOL)

An experiment was conducted to compare the growth and economics of adding organic acids to diets of broiler chickens. The organic acids were sorbic benzoic lactic and propionic acids. 150 day old Hubbard chicks were used. There were five treatments. Diet 1 which served as control contained no organic acid. Diets 2, 3 ...

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...... Regulation (EC) No 1565/2000. None of the substances were considered to have genotoxic potential. The substances were evaluated through a stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern...

The acidic functional groups of humic acid

Energy Technology Data Exchange (ETDEWEB)

Shanxiang, Li; Shuhe, Sun; Zhai Zongxi, Wu Qihu

1983-09-01

The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)

A Facile Method for Detection of Substituted Salicylic Acids Using Pyrenesulfonamide-Terminated Self-Assembled Monolayers on Silicon Oxide Surfaces

Energy Technology Data Exchange (ETDEWEB)

Han, Gyeongyeop; Choi, Jaehyuck; Lee, Jungkyu; Kumar, Ashwani; Lee, Ju-Young; Kim, Hong-Seok [Kyungpook Nation al University, Daegu (Korea, Republic of)

2016-05-15

We have developed a method for sensing substituted salicylic acids on silicon oxide surfaces. The receptor molecule was successfully immobilized onto the surface by self-assembly, and, as a demonstration, micropatterns of substituted salicylic acids were generated by soft lithography techniques. We believe that this approach used herein will not only widen the understanding of the specific interactions between salicylic acids and pyrenesulfonamide derivatives, but also be applicable to practical devices such as chemo/bio analytical sensors. We have successfully demonstrated the molecular recognition between salicylic acids and pyrene derivatives in solution by fluorescence measurement. Briefly, selective recognition was achieved using intermolecular interactions, including π-π interactions and multi-hydrogen bonds, and intramolecular hydrogen bonding between the phenolic O-H group and the adjacent C=O group.

A Facile Method for Detection of Substituted Salicylic Acids Using Pyrenesulfonamide-Terminated Self-Assembled Monolayers on Silicon Oxide Surfaces

International Nuclear Information System (INIS)

Han, Gyeongyeop; Choi, Jaehyuck; Lee, Jungkyu; Kumar, Ashwani; Lee, Ju-Young; Kim, Hong-Seok

2016-01-01

We have developed a method for sensing substituted salicylic acids on silicon oxide surfaces. The receptor molecule was successfully immobilized onto the surface by self-assembly, and, as a demonstration, micropatterns of substituted salicylic acids were generated by soft lithography techniques. We believe that this approach used herein will not only widen the understanding of the specific interactions between salicylic acids and pyrenesulfonamide derivatives, but also be applicable to practical devices such as chemo/bio analytical sensors. We have successfully demonstrated the molecular recognition between salicylic acids and pyrene derivatives in solution by fluorescence measurement. Briefly, selective recognition was achieved using intermolecular interactions, including π-π interactions and multi-hydrogen bonds, and intramolecular hydrogen bonding between the phenolic O-H group and the adjacent C=O group

Mass Spectrometry Analysis Coupled with de novo Sequencing Reveals Amino Acid Substitutions in Nucleocapsid Protein from Influenza A Virus

Directory of Open Access Journals (Sweden)

Zijian Li

2014-02-01

Full Text Available Amino acid substitutions in influenza A virus are the main reasons for both antigenic shift and virulence change, which result from non-synonymous mutations in the viral genome. Nucleocapsid protein (NP, one of the major structural proteins of influenza virus, is responsible for regulation of viral RNA synthesis and replication. In this report we used LC-MS/MS to analyze tryptic digestion of nucleocapsid protein of influenza virus (A/Puerto Rico/8/1934 H1N1, which was isolated and purified by SDS poly-acrylamide gel electrophoresis. Thus, LC-MS/MS analyses, coupled with manual de novo sequencing, allowed the determination of three substituted amino acid residues R452K, T423A and N430T in two tryptic peptides. The obtained results provided experimental evidence that amino acid substitutions resulted from non-synonymous gene mutations could be directly characterized by mass spectrometry in proteins of RNA viruses such as influenza A virus.

Synthesis, characterization and antibacterial activity of new salicylhydrazide containing azopyrazoles

Directory of Open Access Journals (Sweden)

Bhupendra P. Patel

2011-03-01

Full Text Available Various ethyl-2-substituted phenyl hydrazono-3-oxobutyrate (2a-h condensation with 2-hydroxy benzoic acid hydrazide (3 to afford 1-(2-hydroxybenzoyl-3-methyl-4-(2- substituted phenyl hydrazono-1H-pyrazol-5(4H-one (4a-h. The structures of all these compounds (4a-h were recognized on basis of analytical and spectral data. The newly synthesized compounds were evaluated for their antimicrobial activity against various bacteria and fungi.

Synthesis of novel N1-substituted bicyclic pyrazole amino acids and evaluation of their interaction with glutamate receptors

DEFF Research Database (Denmark)

Conti, Paola; Grazioso, Giovanni; di Ventimiglia, Samuele Joppolo

2005-01-01

N1-substituted bicyclic pyrazole amino acids (S)-9a-9c and (R)-9a-9c, which are conformationally constrained analogues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested for activity at ionotropic and metabotropic glutamate receptors...

Identification by random forest method of HLA class I amino acid substitutions associated with lower survival at day 100 in unrelated donor hematopoietic cell transplantation.

Science.gov (United States)

Marino, S R; Lin, S; Maiers, M; Haagenson, M; Spellman, S; Klein, J P; Binkowski, T A; Lee, S J; van Besien, K

2012-02-01

The identification of important amino acid substitutions associated with low survival in hematopoietic cell transplantation (HCT) is hampered by the large number of observed substitutions compared with the small number of patients available for analysis. Random forest analysis is designed to address these limitations. We studied 2107 HCT recipients with good or intermediate risk hematological malignancies to identify HLA class I amino acid substitutions associated with reduced survival at day 100 post transplant. Random forest analysis and traditional univariate and multivariate analyses were used. Random forest analysis identified amino acid substitutions in 33 positions that were associated with reduced 100 day survival, including HLA-A 9, 43, 62, 63, 76, 77, 95, 97, 114, 116, 152, 156, 166 and 167; HLA-B 97, 109, 116 and 156; and HLA-C 6, 9, 11, 14, 21, 66, 77, 80, 95, 97, 99, 116, 156, 163 and 173. In all 13 had been previously reported by other investigators using classical biostatistical approaches. Using the same data set, traditional multivariate logistic regression identified only five amino acid substitutions associated with lower day 100 survival. Random forest analysis is a novel statistical methodology for analysis of HLA mismatching and outcome studies, capable of identifying important amino acid substitutions missed by other methods.

Efficacy of fatty acid chemistry : candidate mold and decay fungicides

Science.gov (United States)

Robert Coleman; Vina Yang; Bessie Woodward; Patti Lebow; Carol Clausen

2010-01-01

Although organic, lipophilic acids, such as acetic, propionic, sorbic and benzoic, have a long history as preservatives in the food industry, relatively high concentrations are required and their bioactivities generally pertain to retarding microbial growth rather than eliminating pathogens. Moreover, exclusive use of organic acids such as lactic or citric acid, alone...

UPS and DFT investigation of the electronic structure of gas-phase trimesic acid

Energy Technology Data Exchange (ETDEWEB)

Reisberg, L., E-mail: rebban@ut.ee [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Pärna, R. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); MAX IV Laboratory, Lund University, Fotongatan 2, 225 94 Lund (Sweden); Kikas, A.; Kuusik, I.; Kisand, V. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Hirsimäki, M.; Valden, M. [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, FIN-33101 Tampere (Finland); Nõmmiste, E. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia)

2016-11-15

Highlights: • In the current study outer valence band electronic structure of benzene-1,3,5-tricarboxylic acid was interpreted. • Experimental and calculated trimesic acid (TMA) spectrum were compared to ones of benzene and benzoic acid. • It is shown that similarities between MO energies and shapes for benzene and TMA exists. • Addition of carboxyl groups to the benzene ring clearly correlates with increasing binding energy of HOMO. - Abstract: Benzene-1,3,5-tricarboxylic acid (trimesic acid, TMA) molecules in gas-phase have been investigated by using valence band photoemission. The photoelectron spectrum in the binding energy region from 9 to 22 eV is interpreted by using density functional theory calculations. The electronic structure of TMA is compared with benzene and benzoic acid in order to demonstrate changes in molecular orbital energies induced by addition of carboxyl groups to benzene ring.

Acid-base and coordination properties of Meso-substituted porphyrins in nonaqueous solutions

Science.gov (United States)

Pukhovskaya, S. G.; Nam, Dao Tkhe; Fien, Chan Ding; Domanina, E. N.; Ivanova, Yu. B.; Semeikin, A. S.

2017-09-01

Acid-base and coordination properties of alkyl and aryl meso-substituted porphyrins are studied spectrophotometrically in nonaqueous solutions. It is found that the nature of the substituent greatly affects the basicity of ligands for porphyrins characterized by a flat structure of macrocycle. The electronic effects of substituents have a much weaker influence on the kinetics of complexing. These effects could be due to the opposite orientation of some factors: an increase in the basicity and stability of the N-H bonds of porphyrin reaction centers. Dissociation constants p K b of the cationic forms of meso-substituted derivatives of porphyrin are measured. The values of p K b are in good agreement with classic concepts of the nature of substituents, particularly those indirectly included in the macrocycle through phenyl buffer rings.

Amino Acid Substitution in Trichophyton rubrum Squalene Epoxidase Associated with Resistance to Terbinafine

Science.gov (United States)

Osborne, Colin S.; Leitner, Ingrid; Favre, Bertrand; Ryder, Neil S.

2005-01-01

There has only been one clinically confirmed case of terbinafine resistance in dermatophytes, where six sequential Trichophyton rubrum isolates from the same patient were found to be resistant to terbinafine and cross-resistant to other squalene epoxidase (SE) inhibitors. Microsomal SE activity from these resistant isolates was insensitive to terbinafine, suggesting a target-based mechanism of resistance (B. Favre, M. Ghannoum, and N. S. Ryder, Med. Mycol. 42:525-529, 2004). In this study, we have characterized at the molecular level the cause of the resistant phenotype of these clinical isolates. Cloning and sequencing of the SE gene and cDNA from T. rubrum revealed the presence of an intron in the gene and an open reading frame encoding a protein of 489 residues, with an equivalent similarity (57%) to both yeast and mammalian SEs. The nucleotide sequences of SE from two terbinafine-susceptible strains were identical whereas those of terbinafine-resistant strains, serially isolated from the same patient, each contained the same single missense introducing the amino acid substitution L393F. Introduction of the corresponding substitution in the Candida albicans SE gene (L398F) and expression of this gene in Saccharomyces cerevisiae conferred a resistant phenotype to the transformants when compared to those expressing the wild-type sequence. Terbinafine resistance in these T. rubrum clinical isolates appears to be due to a single amino acid substitution in SE. PMID:15980358

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage▿

OpenAIRE

Broberg, Anders; Jacobsson, Karin; Ström, Katrin; Schnürer, Johan

2007-01-01

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydro...

Effect of phenols and carboxylic acids on photochromism of 1-alkyl-2-(arylazo)imidazoles

Energy Technology Data Exchange (ETDEWEB)

Gayen, Pallab [Inorganic Chemistry Section, Department of Chemistry, Jadavpur University, Kolkata 700032 (India); Sinha, Chittaranjan, E-mail: c_r_sinha@yahoo.com [Inorganic Chemistry Section, Department of Chemistry, Jadavpur University, Kolkata 700032 (India)

2012-09-15

Light irradiated trans-to-cis isomerization of 1-alkyl-2-(arylazo)imidazole in the presence of phenol, catechol, benzoic acid and salicylic acid (called co-factors) has been studied in this work. The rate of trans{yields}cis photoisomerization is decreased in the presence of co-factor in the medium and is dependent on the concentration of active quotient about photochrome. The decrease in rate follows catechol>benzoic acid>phenol>salicylic acid. This trend is due to the effects of dissociation ability of -O-H/-COOH, intermolecular association of the molecules etc. The reverse change, cis-to-trans, is very slow in light irradiation and has been carried out by a thermal process in the dark. The quantum yield of isomerization follows the same sequence of effects of co-factors. - Highlights: Black-Right-Pointing-Pointer Photoisomerisation of 1-alkyl-2-(arylazo)imidazoles, trans-to-cis, is described in this work. Black-Right-Pointing-Pointer The process is sensitive to the environment of the photochrome and the solution. Black-Right-Pointing-Pointer The rate of photoisomerization decreases as catechol>benzoic acid>phenol>salicylic acid. Black-Right-Pointing-Pointer The reverse isomerization, cis-to-trans is very slow with light and has been carried out with heat. Black-Right-Pointing-Pointer The activation energy is less than these values when carried out in fresh solution only.

A focused fragment library targeting the antibiotic resistance enzyme - Oxacillinase-48: Synthesis, structural evaluation and inhibitor design.

Science.gov (United States)

Akhter, Sundus; Lund, Bjarte Aarmo; Ismael, Aya; Langer, Manuel; Isaksson, Johan; Christopeit, Tony; Leiros, Hanna-Kirsti S; Bayer, Annette

2018-02-10

β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β-lactamases, is the development of β-lactamase inhibitors and today several β-lactamase inhibitors e.g. avibactam, are approved in the clinic. Our focus is the oxacillinase-48 (OXA-48), an enzyme reported to spread rapidly across the world and commonly identified in Escherichia coli and Klebsiella pneumoniae. To guide inhibitor design, we used diversely substituted 3-aryl and 3-heteroaryl benzoic acids to probe the active site of OXA-48 for useful enzyme-inhibitor interactions. In the presented study, a focused fragment library containing 49 3-substituted benzoic acid derivatives were synthesised and biochemically characterized. Based on crystallographic data from 33 fragment-enzyme complexes, the fragments could be classified into R 1 or R 2 binders by their overall binding conformation in relation to the binding of the R 1 and R 2 side groups of imipenem. Moreover, binding interactions attractive for future inhibitor design were found and their usefulness explored by the rational design and evaluation of merged inhibitors from orthogonally binding fragments. The best inhibitors among the resulting 3,5-disubstituted benzoic acids showed inhibitory potential in the low micromolar range (IC 50  = 2.9 μM). For these inhibitors, the complex X-ray structures revealed non-covalent binding to Arg250, Arg214 and Tyr211 in the active site and the interactions observed with the mono-substituted fragments were also identified in the merged structures. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Substituted Amides of Pyrazine-2-carboxylic acids: Synthesis and Biological Activity

Directory of Open Access Journals (Sweden)

Katarina Kralova

2002-03-01

Full Text Available Condensation of 6-chloro-, 5-tert-butyl- or 6-chloro-5-tert-butylpyrazine-2-carboxylic acid chloride with ring substituted anilines yielded a series of amides, which were tested for their in vitro antimycobacterial, antifungal and photosynthesis-inhibiting activities. The highest antituberculotic activity (72% inhibition against Mycobacterium tuberculosis and the highest lipophilicity (log P = 6.85 were shown by the 3,5-bistrifluoromethylphenyl amide of 5-tert-butyl-6-chloropyrazine-2-carboxylic acid (2o. The 3-methylphenyl amides of 6-chloro- and 5-tert-butyl-6-chloro-pyrazine-2-carboxylic acid (2d and 2f exhibited only a poor in vitro antifungal effect (MIC = 31.25-500 μmol·dm-3 against all strains tested, although the latter was the most active antialgal compound (IC50 = 0.063 mmol·dm-3. The most active inhibitor of oxygen evolution rate in spinach chloroplasts was the (3,5-bis-trifluoromethylphenylamide of 6-chloropyrazine-2-carboxylic acid (2m, IC50 = 0.026 mmol·dm-3.

Studies on electrochemical hydrodebromination mechanism of 2,5-dibromobenzoic acid on Ag electrode by in situ FTIR spectroscopy

International Nuclear Information System (INIS)

Li Meichao; Bao Dandan; Ma Chunan

2011-01-01

Research highlights: → Silver is a good catalyst for the hydrodebromination of 2,5-dibromobenzoic acid. → 3-Bromobenzoic acid as main intermediate product. → The finally product is benzoic acid. → In situ FTIR is useful to study the electrochemical hydrodebromination mechanism. - Abstract: Cyclic voltammetry and in situ FTIR were employed to study the electrochemical hydrodebromination (EHB) mechanism of 2,5-dibromobenzoic acid (2,5-DBBA) in NaOH solution. Compared with titanium and graphite electrodes, silver electrode exhibited a high electrocatalytic activity for the hydrodebromination reaction of 2,5-DBBA. On the basis of in situ FTIR data, EHB reaction of 2,5-DBBA on Ag cathode might be represented as a sequence of electron additions and bromine expulsions. Firstly, from potential at approximately -1100 mV, 2,5-DBBA received an electron to form 2,5-DBBA radical anion, which lost a bromine ion in the 2-position to form 3-bromobenzoic acid (3-BBA) free radical. Then the free radical received a proton to give 3-BBA. Finally, 3-BBA further took off another bromine ion to produce benzoic acid free radical and the end product benzoic acid was obtained by receiving another electron and a proton with the potential shifting to more negative values.

Lewis acid tuned facial stereodivergent HDA reactions using beta-substituted N-vinyloxazolidinones.

Science.gov (United States)

Gohier, Frédéric; Bouhadjera, Keltoum; Faye, Djibril; Gaulon, Catherine; Maisonneuve, Vincent; Dujardin, Gilles; Dhal, Robert

2007-01-18

The [4 + 2] acido-catalyzed heterocycloaddition between new beta-substituted N-vinyl-1,3-oxazolidin-2-ones (with R' = Me, Ar, CH2 Ar) and beta,gamma-unsaturated alpha-ketoesters (R = Ar) afforded heteroadducts with high levels of endo and facial selectivities. A complete reversal of facial differentiation was achieved by varying the Lewis acid, leading to the stereoselective formation of either endo-alpha or endo-beta adducts. [reaction: see text].

3-[(E-(2,4-Dichloropbenzylideneamino]benzoic acid

Directory of Open Access Journals (Sweden)

Adnan Ashraf

2011-01-01

Full Text Available In the crystal of the title compound, C14H9Cl2NO2, inversion-related dimers with R22(8 ring motifs are formed by intermolecular O—H...O hydrogen bonding. The 3-aminobenzoic acid group and the 2,4-dichlobenzaldehyde moiety subtend a dihedral angle of 55.10 (2°. The H atom of the carboxyl group is disordered over two sites with equal occupancies.

Substitution of trans fatty acids in foods on the Danish market

DEFF Research Database (Denmark)

Bysted, Anette; Mikkelsen, Aase Ærendahl; Leth, Torben

2009-01-01

Three surveys of the content of trans fatty acids (TFA) in foods on the Danish market were carried out before and after the Danish regulation was introduced in January 2004 restricting the use of industrially produced (IP)-TFA to a maximum of 2 g per 100 g fat in any food product. For this purpose......, food samples were collected in 2002-3, 2004-5, and 2006-7. Of these, 60 paired samples (defined as samples included in two of the three investigations and with higher levels of IP-TFA in the first determination than in the second) were identified. Comparisons of the fatty acid profiles showed that......, in 68% of the products (e.g. sweets, cakes and cookies as well as fast food such as pie and tortilla), IP-TFA were mainly substituted with saturated fatty acids (SFA). In some cases, the SFA source was coconut fat, whereas in other products, palm oil was added instead of partially hydrogenated oils...

Contribution of single amino acid and codon substitutions to the production and secretion of a lipase by Bacillus subtilis.

Science.gov (United States)

Skoczinski, Pia; Volkenborn, Kristina; Fulton, Alexander; Bhadauriya, Anuseema; Nutschel, Christina; Gohlke, Holger; Knapp, Andreas; Jaeger, Karl-Erich

2017-09-25

Bacillus subtilis produces and secretes proteins in amounts of up to 20 g/l under optimal conditions. However, protein production can be challenging if transcription and cotranslational secretion are negatively affected, or the target protein is degraded by extracellular proteases. This study aims at elucidating the influence of a target protein on its own production by a systematic mutational analysis of the homologous B. subtilis model protein lipase A (LipA). We have covered the full natural diversity of single amino acid substitutions at 155 positions of LipA by site saturation mutagenesis excluding only highly conserved residues and qualitatively and quantitatively screened about 30,000 clones for extracellular LipA production. Identified variants with beneficial effects on production were sequenced and analyzed regarding B. subtilis growth behavior, extracellular lipase activity and amount as well as changes in lipase transcript levels. In total, 26 LipA variants were identified showing an up to twofold increase in either amount or activity of extracellular lipase. These variants harbor single amino acid or codon substitutions that did not substantially affect B. subtilis growth. Subsequent exemplary combination of beneficial single amino acid substitutions revealed an additive effect solely at the level of extracellular lipase amount; however, lipase amount and activity could not be increased simultaneously. Single amino acid and codon substitutions can affect LipA secretion and production by B. subtilis. Several codon-related effects were observed that either enhance lipA transcription or promote a more efficient folding of LipA. Single amino acid substitutions could improve LipA production by increasing its secretion or stability in the culture supernatant. Our findings indicate that optimization of the expression system is not sufficient for efficient protein production in B. subtilis. The sequence of the target protein should also be considered as an

Elucidating adsorption mechanisms of phthalate esters upon carbon nanotubes/graphene and natural organic acid competitive effects in water by DFT and MD calculations

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhuang; Wang, Se; Chen, Min Dong; Xu, Defu [Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu KeyLaboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School ofEnvironmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing (China); Tang, Lili [Jiangsu Environmental Monitoring Centre, Nanjing (China); Wang, Degao [Dept. of Environmental Science and Engineering, Dalian Maritime University, Dalian (China)

2015-06-15

Simulations at multiple levels were performed to investigate the aqueous adsorption of phthalate esters (PAEs) on carbon nanoparticles and to find the competitive effect of a low molecular weight natural organic acid (benzoic acid) on the adsorption process. Six PAEs of varying alkyl side chain lengths and three carbon-based nanomaterials including a single-walled carbon nanotube (SWNT), double-walled carbon nanotube (DWNT), and graphene (G) were studied. Results showed that the adsorption energies calculated using density functional theory increase with increasing length of the PAE alkyl chain. G exhibits higher adsorption capacity for the PAEs than SWNT and DWNT. The absolute adsorption energies of these systems also display a positive linear correlation with the hydrophobicity of the PAE molecules. Molecular dynamics simulations indicate that the presence of neutral/anionic benzoic acid in water alleviates the PAE adsorption. Furthermore, anionic benzoic acid exerts more impact on the PAE adsorption than the neutral form.

Synthesis and Structural Characterization of 1- and 2-Substituted Indazoles: Ester and Carboxylic Acid Derivatives

Directory of Open Access Journals (Sweden)

Isabel Bento

2006-11-01

Full Text Available A series of indazoles substituted at the N-1 and N-2 positions with ester-containing side chains -(CH2nCO2R of different lengths (n = 0-6, 9, 10 are described.Nucleophilic substitution reactions on halo esters (X(CH2nCO2R by 1H-indazole inalkaline solution lead to mixtures of N-1 and N-2 isomers, in which the N-1 isomerpredominates. Basic hydrolysis of the ester derivatives allowed the synthesis of thecorresponding indazole carboxylic acids. All compounds were fully characterised bymultinuclear NMR and IR spectroscopies, MS spectrometry and elemental analysis; theNMR spectroscopic data were used for structural assignment of the N-1 and N-2 isomers.The molecular structure of indazol-2-yl-acetic acid (5b was determined by X-raydiffraction, which shows a supramolecular architecture involving O2-H...N1intermolecular hydrogen bonds.

Kinetic resolution and stereoselective synthesis of 3-substituted aspartic acids by using engineered methylaspartate ammonia lyases.

Science.gov (United States)

Raj, Hans; Szymanski, Wiktor; de Villiers, Jandré; Puthan Veetil, Vinod; Quax, Wim J; Shimamoto, Keiko; Janssen, Dick B; Feringa, Ben L; Poelarends, Gerrit J

2013-08-19

Enzymatic amino acid synthesis: Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described. These biocatalytic methodologies for the selective preparation of aspartic acid derivatives appear to be attractive alternatives for existing chemical methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Concise Synthesis and the Antibacterial Activity of 5,6-Dimethoxynaphthalene-2-carboxylic Acid

OpenAIRE

GÖKSU, Süleyman; UĞUZ, Metin Tansu

2014-01-01

5,6-Dimethoxynaphthalene-2-carboxylic acid was synthesized in 7 steps and with an overall yield of 46%. Bromination of 2-naphthol, and methylation with dimethyl sulfate followed by Friedel-Crafts acylation with AcCl gave 2-acetyl-5-bromo-6-methoxynaphthalene. 2-Acetyl-5-bromo-6-methoxynaphthalene was converted to 5-bromo-6- methoxynaphthalene-2-carboxylic acid by a haloform reaction. The esterification of the acid with methanol, methoxylation with NaOCH3 in the presence of CuI and s...

Correction: Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones.

Science.gov (United States)

Yin, Feng; Garifullina, Ainash; Tanaka, Fujie

2018-04-25

Correction for 'Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones' by Feng Yin et al., Org. Biomol. Chem., 2017, 15, 6089-6092.

Study of Substituted Ester Formation in Red Wine by the Development of a New Method for Quantitative Determination and Enantiomeric Separation of Their Corresponding Acids.

Science.gov (United States)

Lytra, Georgia; Franc, Celine; Cameleyre, Margaux; Barbe, Jean-Christophe

2017-06-21

A new method was developed for quantifying substituted acids including, where applicable, their various unexplored enantiomeric forms. A new step was added to acids' usual quantification methods, consisting of extraction, derivatization to methyl esters, and gas chromatography analysis: preliminary extraction was performed at basic pH to eliminate ethyl esters, thus avoiding their transesterification during derivatization. Quantitation and enantiomeric distribution of some substituted esters and their corresponding acids were established in 31 commercial Bordeaux red wines from 0 to 20 years old. A strong positive correlation was observed between the age of wine and levels of ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, ethyl 2-methylbutanoate, ethyl (3R)-3-hydroxybutanoate, both enantiomeric forms of ethyl 2-hydroxy-3-methylbutanoate, and ethyl (2S)-2-hydroxy-4-methylpentanoate, but not ethyl (3S)-3-hydroxybutanoate. However, the standard deviations of average concentrations for the corresponding substituted acids were so large that only few correlations between concentrations and age were observed. Concentrations of (2S)-2-hydroxy-3-methylbutanoic acid and (2S)-2-hydroxy-4-methylpentanoic acid increased slightly over time, while (2R)-2-hydroxy-4-methylpentanoic acid levels decreased slightly with the age. Variations in the ratio of substituted ethyl esters to their corresponding acids over time detected thanks to these analytical advances suggested that, in general, acids were continuously esterified during aging.

Radioiodination via isotope exchange in pivalic acid

International Nuclear Information System (INIS)

Weichert, J.P.; Van Dort, M.E.; Groziak, M.P.; Counsell, R.E.

1986-01-01

A variety of benzoic and aryl aliphatic mono and polyiodinated acids and esters (sterol, triglyceride) were radioiodinated in 55-99% radiochemical yield by isotope exchange with Na 125 i in a melt of pivalic acid. In general, the reaction was complete in 1 h at 155 0 C with little or no substrate decomposition. High specific activity studies afforded 125 I-labeled iopanoic acid with a specific activity of over 700 Ci/mmol. (author)

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.

Reactivity of cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids with diazodiphenylmethane in aprotic solvents

Directory of Open Access Journals (Sweden)

VERA V. KRSTIC

2000-12-01

Full Text Available Rate constants for the reaction of diazodiphenylmethane with cyclohex-1-enylcarboxylic acid and 2-methylcyclohex-1-enylcarboxylic acid were determined in nine aprotic solvents, as well as in seven protic solvents, at 30°C using the appropriate UV-spectroscopic method. In protic solvents the unsubsituted acid displayed higher reaction rates than the methyl-substituted one. The results in aprotic solvents showed quite the opposite, and the reaction rates were considerably lower. In order to explain the obtained results through solvent effects, reaction rate constants (k of the examined acids were correlated using the total solvatochromic equation of the form: log k=logk0+sp*+aa+bb, where p* is the measure of the solvent polarity, a represents the scale of the solvent hydrogen bond donor acidities (HBD and b represents the scale of the solvent hydrogen bond acceptor basicities (HBA. The correlation of the kinetic data were carried out by means of multiple linear regression analysis and the opposite effects of aprotic solvents, as well as the difference in the influence of protic and aprotic solvents on the reaction of the two examined acids with DDM were discussed. The results presented in this paper for cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids were compared with the kinetic data for benzoic acid obtained in the same chemical reaction, under the same experimental conditions.

Adjuvant effects and antiserum action potentiation by a (herbal) compound 2-hydroxy-4-methoxy benzoic acid isolated from the root extract of the Indian medicinal plant 'sarsaparilla' (Hemidesmus indicus R. Br.).

Science.gov (United States)

Alam, M I; Gomes, A

1998-10-01

The adjuvant effect and antiserum potentiation of a compound 2-hydroxy-4-methoxy benzoic acid were explored in the present investigation. This compound, isolated and purified from the Indian medicinal plant Hemidesmus indicus R. Br, possessed antisnake venom activity. Rabbits immunized with Vipera russellii venom in the presence and absence of the compound along with Freund's complete adjuvant, produced a precipitating band in immunogel diffusion and immunogel electrophoresis. The venom neutralizing capacity of this antiserum showed positive adjuvant effects as evident by the higher neutralization capacity (lethal and hemorrhage) when compared with the antiserum raised with venom alone. The pure compound potentiated the lethal action neutralization of venom by commercial equine polyvalent snake venom antiserum in experimental models. These observations raised the possibility of the use of chemical antagonists (from herbs) against snake bite, which may provide a better protection in presence of antiserum, especially in the rural parts of India.

Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

International Nuclear Information System (INIS)

Gurzynski, Lukasz; Puszko, Aniela; Ostrzechowska, Agnieszka; Makowski, Mariusz; Chmurzynski, Lech

2006-01-01

(Acid+base) equilibrium constants, involving the acidity (pK a AC ) and cationic homoconjugation constants (in the form of lgK BHB + AC ), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK a AN andlgK BHB + AN ) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity

Potentiometric studies of acid-base interactions in substituted 4-nitropyridine N-oxide systems

Energy Technology Data Exchange (ETDEWEB)

Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Ostrzechowska, Agnieszka [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

2006-05-15

(Acid+base) equilibrium constants, involving the acidity (pK{sub a}{sup AC}) and cationic homoconjugation constants (in the form of lgK{sub BHB{sup +}}{sup AC}), have been determined by the potentiometric method in 13 systems formed by substituted 4-nitropyridine N-oxides in the polar aprotic solvent, acetone (AC). The derivatives covered a wide range of proton-acceptor properties and inherent diversified tendencies towards formation of hydrogen-bonded homocomplexed cations. In addition, the constant values (expressed as pK{sub a}{sup AN}andlgK{sub BHB{sup +}}{sup AN}) for two of the systems studied, N-oxides of 2-methylamino- and 2-ethylamino-4-nitropyridine, were determined in acetonitrile (AN). The acidity constants in the non-aqueous media studied have been found to change in line with their substituent effects and the sequence of acidity changes in water. The values of the cationic homoconjugation constants increased with increasing basicity of the N-oxides and decreased with increasing solvent basicity.

Effect of a bulky lateral substitution by chlorine atom and methoxy group on self-assembling properties of lactic acid derivatives

Czech Academy of Sciences Publication Activity Database

Stojanović, M.; Bubnov, Alexej; Obadović, D.Ž.; Hamplová, Věra; Cvetinov, M.; Kašpar, Miroslav

2014-01-01

Roč. 146, 1-2 (2014), s. 18-25 ISSN 0254-0584 R&D Projects: GA ČR GA13-14133S Grant - others:AVČR(CZ) M100101204 Institutional support: RVO:68378271 Keywords : ferroelectric liquid crystal * lactic acid derivative * lateral substitution * methoxy group * chlorine substitution * dielectric spectroscopy Subject RIV: JJ - Other Materials Impact factor: 2.259, year: 2014

Aggregation of dialkyl-substituted diphosphonic acids and its effect on metal ion extraction.

Energy Technology Data Exchange (ETDEWEB)

Chiarizia, R.; Barrans, R. E., Jr.; Ferraro, J. R. Herlinger, A. W.; McAlister, D. R.

1999-10-22

Solvent extraction reagents containing the diphosphonic acid group exhibit an extraordinary affinity for tri-, tetra- and hexavalent actinides. Their use has been considered for actinide separation and pre-concentration procedures. Solvent extraction data obtained with P,P{prime}-di(2-ethylhexyl) methane-, ethane- and butanediphosphonic acids exhibit features that are difficult to explain without Knowledge of the aggregation state of the extractants. Information about the aggregation of the dialkyl-substituted diphosphonic acids in aromatic diluents has been obtained using the complementary techniques of vapor pressure osmometry (VPO), small angle neutron scattering (SANS), infrared spectroscopy and molecular mechanics. The results from these techniques provide an understanding of the aggregation behavior of these extractants that is fully compatible with the solvent extraction data. The most important results and their relevance to solvent extraction are reviewed in this paper.

benzoic acid Schiff base and evaluation as corrosion

African Journals Online (AJOL)

user

acid Schiff base and evaluation as corrosion inhibitor of steel in 2.0 M H2SO4. *. 1. ECHEM .... adopted for this experiment was in accordance with .... Table 4: Kinetic data for mild steel corrosion in 2M H2SO4 containing SBDAB from weight loss measurement. inhibitor .... and anti-bacterial activity of Schiff base derived.

Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid

Directory of Open Access Journals (Sweden)

Ioannis eDiakogiannis

2013-06-01

Full Text Available This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH, the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (Tm of cellular lipids of each adapted culture was measured and compared with unexposed cells. The Tm of extracted lipids was measured by Differential Scanning Calorimetry (DSC. A trend of increasing Tm values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in Tm value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased Tm values were measured. The Tm changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased Tm. Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

Kinetics of the reaction of 5-substituted orotic acids with diazodiphenylmethane

Directory of Open Access Journals (Sweden)

ALEKSANDAR D. MARINKOVIC

2004-11-01

Full Text Available Rate konstants for the reaction of eight 5-substituted orotic acids with diazodiphenylmethane (DDM in dimethylformamide (DMF were determined at 30 ºC by the known spectrophotometric method. The determined rate constants were correlated with the equations: log k2 = as1 + bsR + h log k2 = as1 + bsR + yn + h to detect the presence and investigate the influence of both electrical and steric substituent effects. The obtained results show that the electrical effect (the localized – field and delocalized – resonance is predominant and that the steric effect, althought present, is releatively small in this reaction.

Determination and structural correlation of the pKa values of p-substituted trans-2,3-epoxy-4-oxo-4-phenylbutanoic acids

Directory of Open Access Journals (Sweden)

I. JURANIC

2000-11-01

Full Text Available The pKa values for a series of eight p-substituted trans-2,3-epoxy-4-phenyl butanoic acids (p-substituted trans-b-aroylepoxyacrylic acids have been determined potentiometrically in aqueous media at 25°C at an ionic strength of 0.1 mol/dm3 (NaCl. The transmission of polar effects from the substituents on the phenyl nucleus to the carboxylic group through the side chain involving a carbonyl group and an epoxide ring was investigated. The pKa values were correlated with structure using the Hammett, Taft and Yukawa-Tsuno approaches. The Hammett r constant (0.34 was compared with analogue values for structurally similar acids.

Internalisation of hybrid titanium dioxide/para-amino benzoic acid nanoparticles in human dendritic cells did not induce toxicity and changes in their functions.

Science.gov (United States)

Migdal, Camille; Rahal, Raed; Rubod, Alain; Callejon, Sylvie; Colomb, Evelyne; Atrux-Tallau, Nicolas; Haftek, Marek; Vincent, Claude; Serres, Mireille; Daniele, Stéphane

2010-11-10

Nanoparticles (NPs) have been reported to penetrate into human skin through lesional skin or follicular structures. Therefore, their ability to interact with dendritic cell (DC) was investigated using DCs generated from monocytes (mono-DCs). Hybrid titanium dioxide/para-amino benzoic acid (TiO(2)/PABA) NPs did not induce any cell toxicity. NPs were internalised into DCs through macropinocytosis and not by a receptor-mediated mechanism. Confocal microscopy showed that NPs were not detected in the nucleus. These data are confirmed by electronic microscopy which demonstrated that hybrid NPs were rapidly in contact with cellular membrane and localised into cytoplasmic vesicles without colocalisation with clathrin-coated vesicles. Hybrid NPs did not induce CD86 or HLA-DR overexpression or cytokine secretion (IL-8 and TNF-α) indicating no DC activation. Internalisation of hybrid NPs did not modify DC response towards sensitisers such as nickel and thimerosal or LPS used as positive controls. Moreover, hybrid NPs did not induce any oxidative stress implicated in DC activation process. After mono-DC irradiation by ultraviolet A (UVA), hybrid NP-treated cells did not produce UVA-induced reactive oxygen species (ROS) and exhibited a better cell viability compared with UVA-irradiated control cells, suggesting a protecting effect of hybrid TiO(2)/PABA NPs against UVA-induced ROS. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Kinetic Resolution and Stereoselective Synthesis of 3-Substituted Aspartic Acids by Using Engineered Methylaspartate Ammonia Lyases

NARCIS (Netherlands)

Raj, Hans; Szymanski, Wiktor; Villiers, Jandré de; Puthan Veetil, Vinod; Quax, Wim J.; Shimamoto, Keiko; Janssen, Dick B.; Feringa, Ben L.; Poelarends, Gerrit J.

2013-01-01

Kinetic resolution and asymmetric synthesis of various valuable 3-substituted aspartic acids, which were obtained in fair to good yields with diastereomeric ratio values of up to >98:2 and enantiomeric excess values of up to >99 %, by using engineered methylaspartate ammonia lyases are described.

Meso-ester and carboxylic acid substituted BODIPYs with far-red and near-infrared emission for bioimaging applications

KAUST Repository

Ni, Yong

2014-01-21

A series of meso-ester-substituted BODIPY derivatives 1-6 are synthesized and characterized. In particular, dyes functionalized with oligo(ethylene glycol) ether styryl or naphthalene vinylene groups at the α positions of the BODIPY core (3-6) become partially soluble in water, and their absorptions and emissions are located in the far-red or near-infrared region. Three synthetic approaches are attempted to access the meso-carboxylic acid (COOH)-substituted BODIPYs 7 and 8 from the meso-ester-substituted BODIPYs. Two feasible synthetic routes are developed successfully, including one short route with only three steps. The meso-COOH-substituted BODIPY 7 is completely soluble in pure water, and its fluorescence maximum reaches around 650 nm with a fluorescence quantum yield of up to 15 %. Time-dependent density functional theory calculations are conducted to understand the structure-optical properties relationship, and it is revealed that the Stokes shift is dependent mainly on the geometric change from the ground state to the first excited singlet state. Furthermore, cell staining tests demonstrate that the meso-ester-substituted BODIPYs (1 and 3-6) and one of the meso-COOH-substituted BODIPYs (8) are very membrane-permeable. These features make these meso-ester- and meso-COOH-substituted BODIPY dyes attractive for bioimaging and biolabeling applications in living cells. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Meso-ester and carboxylic acid substituted BODIPYs with far-red and near-infrared emission for bioimaging applications

KAUST Repository

Ni, Yong; Zeng, Lintao; Kang, Namyoung; Huang, Kuo-Wei; Wang, Liang; Zeng, Zebing; Chang, Young-Tae; Wu, Jishan

2014-01-01

-6) become partially soluble in water, and their absorptions and emissions are located in the far-red or near-infrared region. Three synthetic approaches are attempted to access the meso-carboxylic acid (COOH)-substituted BODIPYs 7 and 8 from the meso

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.

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.

High fluorescence emission of carboxylic acid functionalized polystyrene/BaTiO{sub 3} nanocomposites and rare earth metal complexes: Preparation and characterization

Energy Technology Data Exchange (ETDEWEB)

Cao, X. T.; Showkat, A. M.; Wang, Z.; Lim, K. T., E-mail: ktlim@pknu.ac.kr [Department of Imaging System Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

2015-03-30

Noble fluorescence nanocomposite compound based on barium titanate nanoparticles (BTO), polystyrene (PSt), and terbium ion (Tb{sup 3+}) was synthesized by a combination of surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization, Friedel-Crafts alkylation reaction and coordinate chemistry. Initially, a modification of surface of BTO was conducted by an exchange process with S-benzyl S’-trimethoxysilylpropyltrithiocarbonate to create macro-initiator for polymerization of styrene. Subsequently, aryl carboxylic acid functionalized polystyrene grafted barium titanate (BTO-g-PSt-COOH) was generated by substitution reaction between 4-(Chloromethyl) benzoic acid and PSt chains. The coordination of the nanohybrids with Tb{sup 3+} ions afforded fluorescent Tb{sup 3+} tagged aryl carboxylic acid functionalized polystyrene grafted barium titanate (BTO-g-PSt-Tb{sup 3+}) complexes. Structure, morphology, and fluorescence properties of nanohybrid complexes were investigated by respective physical and spectral studies. FT-IR and SEM analyses confirmed the formation of BTO-g-PSt-Tb{sup 3+}nanohybrids. Furthermore, TGA profiles demonstrated the grafting of aryl carboxylic acid functionalized polystyrene on BTO surface. Optical properties of BTO-g-PSt-Tb{sup 3+} complexes were investigated by fluorescence spectroscopy.

Radioiodinated 5-iodothienyl-2-substituted long chain fatty acids for myocardial imaging

International Nuclear Information System (INIS)

Goodman, M.M.; Knapp, F.F. Jr.; Kirsch, G.; Owen, B.A.

1984-01-01

Thienyl-2-alkyl derivatives undergo facile iodination regiospecifically at the 5-position of the thiophene ring and are alternatives to iodophenyl agents. /sup 125/I-labeled 2-(17-oxoheptadecanoly)-5-iodothiophene (VIIIa) and /sup 125/I-labeled 2-(13-oxotridecanoyl)-5-iodothiophene (VIIIb) were prepared as model agents. The substrate was 2-(17-oxoheptadecanoyl)thiophene (VIa), in which the thiophene ring was attached to the terminal position of heptadecanoic acid. (VIa) was prepared by Friedel-Crafts condensation of 16-iodohexadecanoyl chloride, with thiophene followed by -I + CN/sup -/ → -CN; Wolff-Kishner reduction; -CN + OH/sup -/ → -COOH (VI). Regiospecific rho-[bis-(trifluoroacety 1)] thallation of (VIa), followed by treatment with KI gave 2-(17-oxoheptadecanoyl)-5-iodothiophene (VIIIa). Compound VIIIb was prepared in the same manner. Compounds Ia, b-VIIIa,b, were analyzed by TLC, IR, MS, NMR, and CandH. I-125-labeled (VIIIa) and (VIIIb) were prepared in the same manner. I-125 (VIIIb) showed high myocardial uptake in rats (4/group). Iodothienyl fatty acids may represent alternatives to iodophenyl substituted fatty acids for myocardial imaging

3,4,5-Tri-dodecyloxybenzoic acid: optimisation and scale-up of the synthesis

NARCIS (Netherlands)

Hersmis, M.C.; Spiering, A.J.H.; Waterval, R.J.M.; Meuldijk, J.; Vekemans, J.A.J.M.; Hulshof, L.A.

2001-01-01

The synthesis of tris-O-dodecyl-gallic acid [3,4,5-tris(dodecyloxy)benzoic acid] - a versatile building block for org. liq. cryst. materials - has been selected for fine chem. scale-up. A large-scale procedure of the alkylation of Me gallate with dodecyl bromide was optimized with exptl. design

Amino acid substitutions in the thymidine kinase gene of induced acyclovir-resistant herpes simplex virus type 1

Science.gov (United States)

Hussin, Ainulkhir; Nor, Norefrina Shafinaz Md; Ibrahim, Nazlina

2013-11-01

Acyclovir (ACV) is an antiviral drug of choice in healthcare setting to treat infections caused by herpes viruses, including, but not limited to genital herpes, cold sores, shingles and chicken pox. Acyclovir resistance has emerged significantly due to extensive use and misuse of this antiviral in human, especially in immunocompromised patients. However, it remains unclear about the amino acid substitutions in thymidine (TK) gene, which specifically confer the resistance-associated mutation in herpes simplex virus. Hence, acyclovir-resistant HSV-1 was selected at high concentration (2.0 - 4.5 μg/mL), and the TK-gene was subjected to sequencing and genotypic characterization. Genotypic sequences comparison was done using HSV-1 17 (GenBank Accesion no. X14112) for resistance-associated mutation determination whereas HSV-1 KOS, HSV-1 473/08 and HSV clinical isolates sequences were used for polymorphism-associated mutation. The result showed that amino acid substitutions at the non-conserved region (UKM-1: Gln34Lys, UKM-2: Arg32Ser & UKM-5: Arg32Cys) and ATP-binding site (UKM-3: Tyr53End & UKM-4: Ile54Leu) of the TK-gene. These discoveries play an important role to extend another dimension to the evolution of acyclovir-resistant HSV-1 and suggest that selection at high ACV concentration induced ACV-resistant HSV-1 evolution. These findings also expand the knowledge on the type of mutations among acyclovir-resistant HSV-1. In conclusion, HSV-1 showed multiple strategies to exhibit acyclovir resistance, including amino acid substitutions in the TK gene.

Recent Progress in the Development of Supercritical Carbon Dioxide-Soluble Metal Ion Extractants: Aggregation, Extraction, and Solubility Properties of Silicon-Substituted Alkylenediphosphonic Acids

Energy Technology Data Exchange (ETDEWEB)

Dietz, Mark L.; McAlister, Daniel R.; Stepinski, Dominique C.; Zalupski, Peter R.; Dzilawa, Julie A.; Barrans, Richard E.; Hess, J.N.; Rubas, Audris V.; Chiarizia, Renato; Lubbers, Christopher M.; Scurto, Aaron M.; Brennecke, Joan F.; Herlinger, Albert W.

2003-09-11

Partially esterified alkylenediphosphonic acids (DPAs) have been shown to be effective reagents for the extraction of actinide ions from acidic aqueous solution into conventional organic solvents. Efforts to employ these compounds in supercritical fluid extraction have been hampered by their modest solubility in unmodified supercritical carbon dioxide (SC-CO2). In an effort to design DPAs that are soluble in SC-CO2, a variety of silicon-substituted alkylenediphosphonic acids have been prepared and characterized, and their behavior compared with that of conventional alkyl-substituted reagents. Silicon substitution is shown to enhance the CO2-philicity of the reagents, while other structural features, in particular, the number of methylene groups bridging the phosphorus atoms of the extractant, are shown to exert a significant influence on their aggregation and extraction properties. The identification of DPAs combining desirable extraction properties with adequate solubility in SC-CO2 is shown to be facilitated by the application of molecular connectivity indices.

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.

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

International Nuclear Information System (INIS)

Gashnga, Pynsakhiat Miki; Singh, T. Sanjoy; Baul, Tushar S. Basu; Mitra, Sivaprasad

2014-01-01

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

Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1 Viruses.

Directory of Open Access Journals (Sweden)

William T Harvey

2016-04-01

Full Text Available Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1 virus isolates (1997-2009 and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens.

Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1) Viruses

Science.gov (United States)

Harvey, William T.; Benton, Donald J.; Gregory, Victoria; Hall, James P. J.; Daniels, Rodney S.; Bedford, Trevor; Haydon, Daniel T.; Hay, Alan J.; McCauley, John W.; Reeve, Richard

2016-01-01

Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI) assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA) glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1) virus isolates (1997–2009) and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens. PMID:27057693

Stabilization of Angiotensin-(1-7) by key substitution with a cyclic non-natural amino acid.

Science.gov (United States)

Wester, Anita; Devocelle, Marc; Tallant, E Ann; Chappell, Mark C; Gallagher, Patricia E; Paradisi, Francesca

2017-10-01

Angiotensin-(1-7) [Ang-(1-7)], a heptapeptide hormone of the renin-angiotensin-aldosterone system, is a promising candidate as a treatment for cancer that reflects its anti-proliferative and anti-angiogenic properties. However, the peptide's therapeutic potential is limited by the short half-life and low bioavailability resulting from rapid enzymatic metabolism by peptidases including angiotensin-converting enzyme (ACE) and dipeptidyl peptidase 3 (DPP 3). We report the facile assembly of three novel Ang-(1-7) analogues by solid-phase peptide synthesis which incorporates the cyclic non-natural δ-amino acid ACCA. The analogues containing the ACCA substitution at the site of ACE cleavage exhibit complete resistance to human ACE, while substitution at the DDP 3 cleavage site provided stability against DPP 3 hydrolysis. Furthermore, the analogues retain the anti-proliferative properties of Ang-(1-7) against the 4T1 and HT-1080 cancer cell lines. These results suggest that ACCA-substituted Ang-(1-7) analogues which show resistance against proteolytic degradation by peptidases known to hydrolyze the native heptapeptide may be novel therapeutics in the treatment of cancer.

Effect of a bulky lateral substitution by chlorine atom and methoxy group on self-assembling properties of lactic acid derivatives

International Nuclear Information System (INIS)

Stojanović, Maja; Bubnov, Alexej; Obadović, Dušanka Ž.; Hamplová, Věra; Cvetinov, Miroslav; Kašpar, Miroslav

2014-01-01

Several chiral liquid crystalline materials derived from the lactic acid have been studied with the aim to establish the effect of bulky lateral substituents on their self-assembling properties. A chlorine atom and methoxy group have been used as lateral substituents in ortho position to ether group position on phenyl ring far from the chiral centre. All the studied materials possess tilted ferroelectric smectic C* phase in a broad temperature range. In dependence on the molecular structure namely type of lateral substituent and length of the chiral chain, the cholesteric mesophase, orthogonal paraelectric smectic A* and crystal mesophases have been detected. Lateral chlorine substitution results in decrease of both the clearing point and crystallisation temperature as well as in a distinct increase of spontaneous polarization. Bulky methoxy substitution slightly suppresses the spontaneous polarisation but strongly increases the melting point that results in monotropic peculiarity of the SmC* phase. Mesomorphic, spontaneous, structural and dielectric properties of the substituted compounds were established and compared to those of the non-substituted ones in order to contribute to better understanding of the structure–property relationship for such chiral self-assembling materials. - Highlights: • Chiral liquid crystalline materials derived from the lactic acid have been studied. • Effect of bulky lateral substituents on self-assembling properties has been established. • Bulky methoxy substitution suppresses spontaneous polarisation but increases the melting point. • The compounds might have a strong potential for many advanced electro-optic applications

Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production

Directory of Open Access Journals (Sweden)

Sándor B. Ötvös

2013-07-01

Full Text Available The preparation of novel multi-substituted 1,2,3-triazole-modified β-aminocyclohexanecarboxylic acid derivatives in a simple and efficient continuous-flow procedure is reported. The 1,3-dipolar cycloaddition reactions were performed with copper powder as a readily accessible Cu(I source. Initially, high reaction rates were achieved under high-pressure/high-temperature conditions. Subsequently, the reaction temperature was lowered to room temperature by the joint use of both basic and acidic additives to improve the safety of the synthesis, as azides were to be handled as unstable reactants. Scale-up experiments were also performed, which led to the achievement of gram-scale production in a safe and straightforward way. The obtained 1,2,3-triazole-substituted β-aminocyclohexanecarboxylates can be regarded as interesting precursors for drugs with possible biological effects.

Effect of Amidated Low Methoxyl Pectin on the Mechanical Properties and Colour Attributes of Fish Mince

Directory of Open Access Journals (Sweden)

Rocio M. Uresti

2003-01-01

Full Text Available Pectins have been unsuccessfully applied to improve functionality of meat and fish products. Effect of amidated low methoxyl pectin (ALM pectin levels on functionality of Mexican flounder (Cyclopsetta chittendenii mince was studied. Changes in the firmness and work of extrusion of pastes, texture profile analysis (TPA of gels, and colour parameters were determined. ALM pectin at 1 % decreased firmness and work of extrusion of fish pastes but increased hardness, chewiness and cohesiveness of the gels (P<0.05. The addition of ALM pectin increased slightly the whiteness and yellowness of mince gels. Chrome parameter indicated that gels remained in the grayish achromatic region. Therefore ALM pectin at 1 % could be employed to modify the textural properties of fish mince.

Synthesis and characterization of an in situ forming hydrogel using tyramine conjugated high methoxyl gum tragacanth.

Science.gov (United States)

Tavakol, Moslem; Vasheghani-Farahani, Ebrahim; Mohammadifar, Mohammad Amin; Soleimani, Masoud; Hashemi-Najafabadi, Sameereh

2016-02-01

In this study, an enzyme catalyzed in situ forming hydrogel based on tyramine conjugated high methoxyl content gum tragacanth (TA-HMGT) was prepared and characterized. TA-HMGT was synthesized via heterogeneous ammonolysis of methyl ester groups of HMGT. Then, the hydrogel was prepared via horseradish peroxidase catalyzed coupling reaction in the presence of hydrogen peroxide. Hydrogel properties, such as gelation time, swelling/degradation behavior and rheological properties could be adjusted by tuning the gelation parameters and extent of tyramine conjugation. This system was a soft elastic hydrogel with appropriate biocompatibility. The fast gelation of the hydrogel is desirable for clinical applications. Also, in vitro bovine serum albumin release from the synthesized hydrogel showed good release profile with limited burst release. © The Author(s) 2015.

2-arylureidobenzoic acids

DEFF Research Database (Denmark)

Valgeirsson, Jon; Nielsen, Elsebet Ø; Peters, Dan

2003-01-01

A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent...... on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC(50) values of 1.3, 1...

Substitution of Linoleic Acid for Other Macronutrients and the Risk of Ischemic Stroke.

Science.gov (United States)

Venø, Stine K; Schmidt, Erik B; Jakobsen, Marianne U; Lundbye-Christensen, Søren; Bach, Flemming W; Overvad, Kim

2017-12-01

Ischemic stroke is a major health problem worldwide, but the influence of dietary factors on stroke risk is not well known. This study aimed to investigate the risk of ischemic stroke and its subtypes with a higher intake from linoleic acid and a concomitant lower intake from saturated fatty acids, monounsaturated fatty acids, or glycemic carbohydrates. In the Danish prospective Diet, Cancer, and Health Study of 57 053 participants aged 50 to 64 years at baseline, information on diet was collected using a validated semiquantitative food frequency questionnaire. Information on ischemic stroke was obtained from the Danish National Patient Register, and cases were all validated and subclassified according to the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification. Substitution of linoleic acid for saturated fatty acid, monounsaturated fatty acid, or glycemic carbohydrates was investigated in relation to the risk of ischemic stroke and subtypes. Cox proportional hazards regression was used to estimate the associations with ischemic stroke adjusting for appropriate confounders. During 13.5 years of follow-up 1879 participants developed ischemic stroke. A slightly lower risk of ischemic stroke was found with a 5% higher intake of linoleic acid and a concomitant lower intake of saturated fatty acid (hazard ratio, 0.98; 95% confidence interval, 0.83-1.16), monounsaturated fatty acid (hazard ratio, 0.80; 95% confidence interval, 0.63-1.02), and glycemic carbohydrates (hazard ratio, 0.92; 95% confidence interval, 0.78-1.09), although not statistically significant. Similar patterns of association were found for large-artery atherosclerosis and small-vessel occlusions. This study suggests that replacing saturated fatty acid, glycemic carbohydrate, or monounsaturated fatty acid with linoleic acid may be associated with a lower risk of ischemic stroke. © 2017 American Heart Association, Inc.

Multifunctional Cinnamic Acid Derivatives

Directory of Open Access Journals (Sweden)

Aikaterini Peperidou

2017-07-01

Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

The Effect of Synthesis Conditions and Nature of Heteroelement on Acidic Properties of Isomorphously Substituted UTL Zeolites

Czech Academy of Sciences Publication Activity Database

Shamzhy, Mariya; Shvets, O. V.; Opanasenko, Maksym; Vitvarová, Dana; Nachtigall, P.; Čejka, Jiří

2013-01-01

Roč. 1, č. 1 (2013), s. 103-113 ISSN 2327-3941 R&D Projects: GA ČR GBP106/12/G015; GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : Extra-Large Pore Zeolite * Isomorphous Substitution * Brønsted and Lewis Acidity Subject RIV: CF - Physical ; Theoretical Chemistry

Rapid acquisition adaptive amino acid substitutions involved in the virulence enhancement of an H1N2 avian influenza virus in mice.

Science.gov (United States)

Yu, Zhijun; Sun, Weiyang; Zhang, Xinghai; Cheng, Kaihui; Zhao, Chuqi; Xia, Xianzhu; Gao, Yuwei

2017-08-01

Although H1N2 avian influenza virus (AIV) only infect birds, documented cases of swine infection with H1N2 influenza viruses suggest this subtype AIV may pose a potential threat to mammals. Here, we generated mouse-adapted variants of a H1N2 AIV to identify adaptive changes that increased virulence in mammals. MLD 50 of the variants were reduced >1000-fold compared to the parental virus. Variants displayed enhanced replication in vitro and in vivo, and replicate in extrapulmonary organs. These data show that enhanced replication capacity and expanded tissue tropism may increase the virulence of H1N2 AIV in mice. Sequence analysis revealed multiple amino acid substitutions in the PB2 (L134H, I647L, and D701N), HA (G228S), and M1 (D231N) proteins. These results indicate that H1N2 AIV can rapidly acquire adaptive amino acid substitutions in mammalian hosts, and these amino acid substitutions collaboratively enhance the ability of H1N2 AIV to replicate and cause severe disease in mammals. Copyright © 2017 Elsevier B.V. All rights reserved.

A rhodamine chromene-based turn-on fluorescence probe for selectively imaging Cu2+ in living cell

Science.gov (United States)

Liu, Wei-Yong; Li, Hai-Ying; Lv, Hong-Shui; Zhao, Bao-Xiang; Miao, Jun-Ying

We describe the development of a rhodamine chromene-based turn-on fluorescence probe to monitor the intracellular Cu2+ level in living cells. The new fluorescent probe with a chlorine group in chromene moiety exhibits good membrane-permeable property than previous reported because the predicted lipophilicity of present probe 4 is stronger than that of methoxyl substituted probe in our previous work (CLogP of 4: 8.313, CLogP of methoxyl substituted probe: 7.706), and a fluorescence response toward Cu2+ under physiological conditions with high sensitivity and selectivity, and facilitates naked-eye detection of Cu2+. The fluorescence intensity was remarkably increased upon the addition of Cu2+ within 1 or 2 min, while the other sixteen metal ions caused no significant effect.

Human triose-phosphate isomerase deficiency: a single amino acid substitution results in a thermolabile enzyme.

Science.gov (United States)

Daar, I O; Artymiuk, P J; Phillips, D C; Maquat, L E

1986-10-01

Triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1) deficiency is a recessive disorder that results in hemolytic anemia and neuromuscular dysfunction. To determine the molecular basis of this disorder, a TPI allele from two unrelated patients homozygous for TPI deficiency was compared with an allele from a normal individual. Each disease-associated sequence harbors a G X C----C X G transversion in the codon for amino acid-104 and specifies a structurally altered protein in which a glutamate residue is replaced by an aspartate residue. The importance of glutamate-104 to enzyme structure and function is implicated by its conservation in the TPI protein of all species that have been characterized to date. The glutamate-to-aspartate substitution results in a thermolabile enzyme as demonstrated by assays of TPI activity in cultured fibroblasts of each patient and cultured Chinese hamster ovary (CHO) cells that were stably transformed with the mutant alleles. Although this substitution conserves the overall charge of amino acid-104, the x-ray crystal structure of chicken TPI indicates that the loss of a side-chain methylene group (-CH2CH2COO- ---- -CH2COO-) is sufficient to disrupt the counterbalancing of charges that normally exists within a hydrophobic pocket of the native enzyme.

New insights into the acid mediated disproportionation of pentavalent uranyl

Energy Technology Data Exchange (ETDEWEB)

Mougel, Victor; Biswas, Biplab; Pecaut, Jacques; Mazzanti, Marinella [Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E 3 CEA-UJF FRE 3200 CNRS, INAC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France)

2010-07-01

The reaction of benzoic acid with the uranyl(V) complex [(UO{sub 2}Py{sub 5})(KI{sub 2}Py{sub 2})] in pyridine leads to immediate disproportionation with formation of a hexa-nuclear U(IV) benzoate cluster, a bis-benzoate complex of uranyl(VI) and water. (authors)

Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

Science.gov (United States)

Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

2017-02-01

Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potentiometric investigation of acid dissociation and anionic homoconjugation equilibria of substituted phenols in dimethyl sulfoxide

International Nuclear Information System (INIS)

Czaja, Malgorzata; Kozak, Anna; Makowski, Mariusz; Chmurzynski, Lech.

2003-01-01

Standard acidity constants, K a DMSO (HA), expressed as pK a DMSO (HA) values, and anionic homoconjugation constants, K DMSO AHA - , (in the form of lg K DMSO AHA - values) have been determined for 11 substituted phenol-phenolate systems a polar protophilic aprotic solvent, dimethyl sulfoxide (DMSO) with a potentiometric titration. A linear relationship has been determined between lg K DMSO AHA - and pK a DMSO (HA). The tendency towards anionic homoconjugation in these systems increases with increasing pK a DMSO (HA) that is with declining phenol acidity. The pK a DMSO (HA) are correlated with both pK a W (HA) water and other polar non-aqeous solvents

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.

p-Hydroxy benzoic acid-conjugated dendrimer nanotherapeutics as potential carriers for targeted drug delivery to brain: an in vitro and in vivo evaluation

International Nuclear Information System (INIS)

Swami, Rajan; Singh, Indu; Kulhari, Hitesh; Jeengar, Manish Kumar; Khan, Wahid; Sistla, Ramakrishna

2015-01-01

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 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 ® ). Therefore, pHBA conjugated dendrimers could be an efficient delivery vehicle for the targeting of anticancer drugs to brain tumors

p-Hydroxy benzoic acid-conjugated dendrimer nanotherapeutics as potential carriers for targeted drug delivery to brain: an in vitro and in vivo evaluation

Science.gov (United States)

Swami, Rajan; Singh, Indu; Kulhari, Hitesh; Jeengar, Manish Kumar; Khan, Wahid; Sistla, Ramakrishna

2015-06-01

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 1HNMR 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®). Therefore, pHBA conjugated dendrimers could be an efficient delivery vehicle for the targeting of anticancer drugs to brain tumors.

Partial molar volumes of some drug and pro-drug substances in 1-octanol at T = 298.15 K

International Nuclear Information System (INIS)

Manin, Alex N.; Shmukler, Liudmila E.; Safonova, Liubov P.; Perlovich, German L.

2010-01-01

The article deals with measuring the densities of phenol, acetanilide, benzamide, benzoic acid, phenacetin, i-(acetylamino)-benzoic acid, i-hydroxy-benzamide, and i-acetaminophen (where i = 1, 2, 3) in 1-octanol in the wide concentration interval at T = 298.15 K. It also concerns the evaluation of apparent molar volumes and partial molar volumes at infinite dilution, V 2 0 -bar as well as comparative analysis of the free volumes per molecule in the octanolic solutions, V 2 free , and in the crystal lattices, V 2 free (cr), from the nature and position of the substitutes. Also described is the evaluation of the increments of V 2 0 -bar andV 2 free for the unsubstituted molecules and isomers and the methods to obtain partial molar volumes for various functional groups at infinite dilution in 1-octanol at T = 298.15 K. Also considered is the limiting partial molar volume of the solutes in terms of the scaled particle theory.

Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L.

Science.gov (United States)

Agustia, Yuda Virgantara; Suyitno, Arifin, Zainal; Sutanto, Bayu

2016-03-01

The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, EHOMO and ELUMO was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where Ered = -0.37V, ELUMO = -4.28 eV, Eox = 1.15V, EHOMO = -5.83 eV, and Eband gap = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

What makes lithium substituted polyacrylic acid a better binder than polyacrylic acid for silicon-graphite composite anodes?

Science.gov (United States)

Hays, Kevin A.; Ruther, Rose E.; Kukay, Alexander J.; Cao, Pengfei; Saito, Tomonori; Wood, David L.; Li, Jianlin

2018-04-01

Lithium substituted polyacrylic acid (LiPAA) has previously been demonstrated as a superior binder over polyacrylic acid (PAA) for Si anodes, but from where does this enhanced performance arise? In this study, full cells are assembled with PAA and LiPAA based Si-graphite composite anodes that dried at temperatures from 100 °C to 200 °C. The performance of full cells containing PAA based Si-graphite anodes largely depend on the secondary drying temperature, as decomposition of the binder is correlated to increased electrode moisture and a rise in cell impedance. Full cells containing LiPAA based Si-graphite composite electrodes display better Coulombic efficiency than those with PAA, because of the electrochemical reduction of the PAA binder. This is identified by attenuated total reflectance Fourier transform infrared spectrometry and observed gassing during the electrochemical reaction. Coulombic losses from the PAA and Si SEI, along with depletion of the Si capacity in the anode results in progressive underutilization of the cathode and full cell capacity loss.

Dodecatungstocobaltate and Sn (IV)-Substituted Polyoxometalate ...

African Journals Online (AJOL)

NICO

work metals, or substituting different cations for the protons to make their acidic or neutral ... corrosive materials in comparison with traditional Lewis acids. The importance of .... salt by treatment with potassium chloride. Finally, the cobalt (II).

Bioactive phenolic acids from Scorzonera radiata Fisch.

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N Tsevegsuren

2014-09-01

Full Text Available Chromatographic separation of the crude extract obtained from the aerial parts of the Mongolian medicinal plant Scorzonera radiata yielded five new dihydrostilbenes [4], two new flavonoids, one new quinic acid derivative, as well as twenty known compounds including eight quinic acid derivatives, four flavonoids, two coumarins, five simple benzoic acids, and one monoterpene glycoside. We present here results on isolation and structural identification some active phenolic compounds from the Scorzonera radiata - eight quinic acid derivatives (quinic acid, 4,5-dicaffeoylquinic acid, 4,5-dicaffeoyl-epi-quinic acid, 3,5-dicaffeoylquinic acid, 3,5-dicaffeoyl-epi-quinic acid, chlorogenic acid, 5-p-coumaroylquinic acid (trans, 5-p-coumaroylquinic acid (cis. Quinic acid derivatives exhibited antioxidative activity.DOI: http://dx.doi.org/10.5564/mjc.v12i0.177 Mongolian Journal of Chemistry Vol.12 2011: 78-84

Structural and catalytic effects of an invariant purine substitution in the hammerhead ribozyme: implications for the mechanism of acid-base catalysis.

Science.gov (United States)

Schultz, Eric P; Vasquez, Ernesto E; Scott, William G

2014-09-01

The hammerhead ribozyme catalyzes RNA cleavage via acid-base catalysis. Whether it does so by general acid-base catalysis, in which the RNA itself donates and abstracts protons in the transition state, as is typically assumed, or by specific acid-base catalysis, in which the RNA plays a structural role and proton transfer is mediated by active-site water molecules, is unknown. Previous biochemical and crystallographic experiments implicate an invariant purine in the active site, G12, as the general base. However, G12 may play a structural role consistent with specific base catalysis. To better understand the role of G12 in the mechanism of hammerhead catalysis, a 2.2 Å resolution crystal structure of a hammerhead ribozyme from Schistosoma mansoni with a purine substituted for G12 in the active site of the ribozyme was obtained. Comparison of this structure (PDB entry 3zd4), in which A12 is substituted for G, with three previously determined structures that now serve as important experimental controls, allows the identification of structural perturbations that are owing to the purine substitution itself. Kinetic measurements for G12 purine-substituted schistosomal hammerheads confirm a previously observed dependence of rate on the pK(a) of the substituted purine; in both cases inosine, which is similar to G in pK(a) and hydrogen-bonding properties, is unexpectedly inactive. Structural comparisons indicate that this may primarily be owing to the lack of the exocyclic 2-amino group in the G12A and G12I substitutions and its structural effect upon both the nucleotide base and phosphate of A9. The latter involves the perturbation of a previously identified and well characterized metal ion-binding site known to be catalytically important in both minimal and full-length hammerhead ribozyme sequences. The results permit it to be suggested that G12 plays an important role in stabilizing the active-site structure. This result, although not inconsistent with the potential

Acid mine drainage simulated leaching behavior of goethite and cobalt substituted goethite

Science.gov (United States)

Penprase, S. B.; Kimball, B. E.

2015-12-01

Though most modern day mining aims to eliminate the seepage of acid mine drainage (AMD) to the local watershed, historical mines regularly receive little to no remediation, and often release acidic, metal-rich drainage and particles to the environment. Treatment of AMD often includes neutralizing pH to facilitate the precipitation of Fe-oxides and dissolved trace metals, thereby forming Trace Metal Substituted (TMS) forms of known minerals, such as goethite (α-FeOOH). The stability of TMS precipitates is not fully understood. As a result, we conducted a 20 day leach experiment using laboratory synthesized pure (Gt) and cobalt-substituted (CoGt) goethites with a dilute ultrapure HCl solution (pH = 3.61) at T = 23.3±2.5ºC. Leached solids were characterized using X-ray diffraction (XRD) and scanning electron microscopy paired with energy dispersive spectroscopy (SEM-EDS). Leach solutions were sampled for pH and conductivity, and dissolved chemistry was determined with Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Preliminary results indicate Gt and CoGt filtered leach solutions experienced constant pH (Gt = 3.9 ± 0.1, CoGt = 6.8 ± 0.2) and conductivity (Gt = 69 ± 6.6 μS/cm, CoGt = 81 ± 16 μS/cm) for t = 0-20 days. Micro-focused XRD results indicate that leached solids did not change in mineralogy throughout the experiment, and SEM images show minor disintegration along mineral grain edges, but little overall change in shape. Preliminary ICP-MS results show lower dissolved Fe concentrations for CoGt (1.1 ± 1.1 ppb) compared to Gt (17 ± 8.9 ppb) over time. Dissolved Co concentrations ranged from 560 - 830 ppb and increased over time. Compared to leaching of pure Gt, leaching of CoGt generated significantly higher pH, slightly higher conductivity, and significantly less dissolved Fe. During the CoGt leach, Co was preferentially leached over Fe. The differences in leaching behavior between pure and TMS goethite in the laboratory have implications for

A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

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Miguel A Martín-Acebes

Full Text Available West Nile virus (WNV is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu on the highly basic internal capsid or core (C protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

Science.gov (United States)

Martín-Acebes, Miguel A; Blázquez, Ana-Belén; de Oya, Nereida Jiménez; Escribano-Romero, Estela; Shi, Pei-Yong; Saiz, Juan-Carlos

2013-01-01

West Nile virus (WNV) is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu) on the highly basic internal capsid or core (C) protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A) and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

Kinetic Studies on the Oxidation of Some para and meta-Substituted Cinnamic Acids by Pyridinium Bromochromate in the Presence of Oxalic Acid (A Co-oxidation Study

Directory of Open Access Journals (Sweden)

G. Vanangamudi

2009-01-01

Full Text Available The kinetics of oxidation of cinnamic acids by pyridinium bromochromate (PBC in the presence of oxalic acid has been studied in acetic acid-water (60:40% medium. The reaction shows unit order dependence each with respect to oxidant as well as oxalic acid [OX], the order with respect to [H+] and [CA] are fractional. The reaction is acid catalyzed and a low dielectric constant favours the reaction. Increase the ionic strength has no effect on the reaction rate. In the case of substituted cinnamic acids the order with respect to substrate vary depending upon the nature of the substituent present in the ring. In general, the electron withdrawing substituents retard the rate while the electron releasing substituents enhance the rate of reaction. From the kinetic data obtained the activation parameters have been computed and a suitable mechanism has been proposed.

Sample preparation method for the speciation of polybrominated diphenyl ethers and their methoxylated and hydroxylated analogues in diverse environmental matrices.

Science.gov (United States)

Sun, Jianteng; Liu, Jiyan; Liu, Qian; Qu, Guangbo; Ruan, Ting; Jiang, Guibin

2012-01-15

A reliable analytical method was developed here for the simultaneous separation, identification and quantification of ten polybrominated diphenyl ethers (PBDEs), nine methoxylated PBDEs (MeO-PBDEs) and ten hydroxylated PBDEs (OH-PBDEs) in various environmental matrices, including water, soil, sediment, plant, mollusk and fish. PBDEs and MeO-PBDEs were measured by gas chromatography coupled with mass spectrometry (GC/MS) and liquid chromatography coupled with electrospray ionization (negative)-tandem quadrupole mass spectrometry (LC/ESI(-)-MS/MS) for the separation and determination of OH-PBDEs without prior derivatization. After preliminary sample cleaning using acid silica gel, water-impregnated silica column separation of PBDEs, MeO-PBDEs and OH-PBDEs was proved to be rapid, simple, and efficient. For phenolic analytes, the method detection limits (MDLs) were 3.2-11.6pg/L in water sample and 2.8-18.4pg/g dry weight in solid samples. For neutral compounds, MDLs were 48.8-150.3pg/L in water sample and 46.5-170.8pg/g dry weight in solid samples. The method was validated using six kinds of environmental samples spiked with all analytes at three concentration levels (0.3ng, 2ng and 5ng, respectively) for recovery (71-113%) and repeatability determination (4-12%RSD). Copyright © 2011 Elsevier B.V. All rights reserved.

PON-Sol: prediction of effects of amino acid substitutions on protein solubility.

Science.gov (United States)

Yang, Yang; Niroula, Abhishek; Shen, Bairong; Vihinen, Mauno

2016-07-01

Solubility is one of the fundamental protein properties. It is of great interest because of its relevance to protein expression. Reduced solubility and protein aggregation are also associated with many diseases. We collected from literature the largest experimentally verified solubility affecting amino acid substitution (AAS) dataset and used it to train a predictor called PON-Sol. The predictor can distinguish both solubility decreasing and increasing variants from those not affecting solubility. PON-Sol has normalized correct prediction ratio of 0.491 on cross-validation and 0.432 for independent test set. The performance of the method was compared both to solubility and aggregation predictors and found to be superior. PON-Sol can be used for the prediction of effects of disease-related substitutions, effects on heterologous recombinant protein expression and enhanced crystallizability. One application is to investigate effects of all possible AASs in a protein to aid protein engineering. PON-Sol is freely available at http://structure.bmc.lu.se/PON-Sol The training and test data are available at http://structure.bmc.lu.se/VariBench/ponsol.php mauno.vihinen@med.lu.se Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

Energy Technology Data Exchange (ETDEWEB)

Fillaux, François, E-mail: francois.fillaux@upmc.fr [Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-7505 Paris (France); Cousson, Alain, E-mail: alain-f.cousson@cea.fr [Laboratoire Léon Brillouin (CEA-CNRS), C.E. Saclay, 91191 Gif-sur-Yvette cedex (France)

2016-11-10

Highlights: • Proton transfer and tautomerism are revisited from quantum viewpoint. • Neutron-diffraction gives evidence for long-range correlations for protons. • We introduce a decoherence-free macroscopic-scale crystal-state. • All observations accord with the principle of complementarity. • Computational-chemistry models are inappropriate. - Abstract: Measurements via different techniques of the crystal of benzoic acid have led to conflicting conceptions of tautomerism: statistical disorder for diffraction; semiclassical jumps for relaxometry; quantum states for vibrational spectroscopy. We argue that these conflicts follow from the prejudice that nuclear positions and eigenstates are pre-existing to measurements, what is at variance with the principle of complementarity. We propose a self-contained quantum theory. First of all, new single-crystal neutron-diffraction data accord with long-range correlation for proton-site occupancies. Then we introduce a macroscopic-scale quantum-state emerging from phonon condensation, for which nuclear positions and eigenstates are indefinite. As to quantum-measurements, an incoming wave (neutron or photon) entangled with the condensate realizes a transitory state, either in the space of static nuclear-coordinates (diffraction), or in that of the symmetry coordinates (spectroscopy and relaxometry). We derive temperature-laws for proton-site occupancies and for the relaxation rate, which compare favorably with measurements.

Effect of substituted gelling agents from pomegranate peel on colour, textural and sensory properties of pomegranate jam.

Science.gov (United States)

Abid, Mouna; Yaich, Héla; Hidouri, Hayfa; Attia, Hamadi; Ayadi, M A

2018-01-15

A series of pomegranate jams were prepared from a Tunisian ecotype (Tounsi) with different amounts of sugar (10, 20 and 30%) and low-methoxylated pectin (0.2, 0.7 and 1.2%). The most appreciated formulation was that contaning 30% sugars and 0.2% pectin. Then, commercial pectin was substituted by other gelling agents (pomegranate peel powders dried at 50°C vs lyophilized, pectin and fibre extracted from pomegranate peel) for the preparation of pomegranate peel-based jams. The elaborated jams were evaluated for physichochemical, colour, texture and sensory characteristics. Results revealed that the jam (JPP2) elaborated with 0.2% pectin extracted from pomegranate peel exhibited similar overall acceptability to that prepared with commercial pectin. However, it was more acceptable than other pomegranate peel-based jams, which was related to a better appreciation of sweetness and colour. According to the colour and texture measurements, this sample (JPP2) was more reddish and less firm than other samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

The human chorionic gonadotropin-beta arginine68 to glutamic acid substitution fixes the conformation of the C-terminal peptide

DEFF Research Database (Denmark)

Charrel-Dennis, Marie; Terrazzini, Nadia; McBride, Jeffrey D

2005-01-01

Wild-type human chorionic gonadotropin (hCG) has been used as a contraceptive vaccine. However, extensive sequence homology with LH elicits production of cross-reactive antibodies. Substitution of arginine(68) of the beta-subunit (hCG(beta)) with glutamic acid (R68E) profoundly reduces the cross...

Fabrication of calcium phosphate–calcium sulfate injectable bone substitute using hydroxy-propyl-methyl-cellulose and citric acid

Science.gov (United States)

Thai, Van Viet

2010-01-01

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37°C. PMID:20333539

Separation of trivalent actinides and lanthanides with some substituted oligopyridines and triazines in synergy with 2-bromodecanoic acid. (Presented at the International Solvent Extraction Conference, July 1999 in Barcelona)

International Nuclear Information System (INIS)

Enarsson, Aa.; Spjuth, L.; Liljenzin, J.O.; Kaellvenius, G.

2000-01-01

The separation of trivalent actinides and lanthanides with some substituted oligopyridines and triazines in synergy with 2-bromodecanoic acid was studied. All ligands, except the quinolinyl-derivatives, showed high metal extraction and good separation factors for trivalent actinides over lanthanides. The substituted di-pyridyltriazines and the quaterpyridine showed the highest distribution ratios and quater- and quinquepyridine the highest separation factors, at low nitric acid concentration. The basicity of the different ligands were determined by non-aqueous titration in acetonitrile media and was related to the metal extraction. The substituted di-pyridyltriazines, which showed the highest metal extraction also showed the lowest basicity

Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Five-, Six-, and Seven-Membered β-Substituted Cyclic Enones: Enantioselective Construction of All-Carbon Quaternary Stereocenters

KAUST Repository

Kikushima, Kotaro; Holder, Jeffrey C.; Gatti, Michele; Stoltz, Brian M.

2011-01-01

The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a

Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET).

Science.gov (United States)

Bouhlel, Ahlem; Alyami, Wadha; Li, Aixiao; Yuan, Liya; Rich, Keith; McConathy, Jonathan

2016-04-14

Two [(18)F]fluoroalkyl substituted amino acids differing only by the presence or absence of a methyl group on the α-carbon, (S)-2-amino-7-[(18)F]fluoro-2-methylheptanoic acid ((S)-[(18)F]FAMHep, (S)-[(18)F]14) and (S)-2-amino-7-[(18)F]fluoroheptanoic acid ((S)-[(18)F]FAHep, (S)-[(18)F]15), were developed for brain tumor imaging and compared to the well-established system L amino acid tracer, O-(2-[(18)F]fluoroethyl)-l-tyrosine ([(18)F]FET), in the delayed brain tumor (DBT) mouse model of high-grade glioma. Cell uptake, biodistribution, and PET/CT imaging studies showed differences in amino acid transport of these tracer by DBT cells. Recognition of (S)-[(18)F]15 but not (S)-[(18)F]14 by system L amino acid transporters led to approximately 8-10-fold higher uptake of the α-hydrogen substituted analogue (S)-[(18)F]15 in normal brain. (S)-[(18)F]15 had imaging properties similar to those of (S)-[(18)F]FET in the DBT tumor model while (S)-[(18)F]14 afforded higher tumor to brain ratios due to much lower uptake by normal brain. These results have important implications for the future development of α-alkyl and α,α-dialkyl substituted amino acids for brain tumor imaging.

Characterization of Benzoyl Coenzyme A Biosynthesis Genes in the Enterocin-Producing Bacterium “Streptomyces maritimus”

Science.gov (United States)

Xiang, Longkuan; Moore, Bradley S.

2003-01-01

The novel benzoyl coenzyme A (benzoyl-CoA) biosynthesis pathway in “Streptomyces maritimus” was investigated through a series of target-directed mutations. Genes involved in benzoyl-CoA formation were disrupted through single-crossover homologous recombination, and the resulting mutants were analyzed for their ability to biosynthesize the benzoyl-CoA-primed polyketide antibiotic enterocin. Inactivation of the unique phenylalanine ammonia-lyase-encoding gene encP was previously shown to be absolutely required for benzoyl-CoA formation in “S. maritimus”. The fatty acid β-oxidation-related genes encH, -I, and -J, on the other hand, are necessary but not required. In each case, the yield of benzoyl-CoA-primed enterocin dropped below wild-type levels. We attribute the reduced benzoyl-CoA formation in these specific mutants to functional substitution and cross-talk between the products of genes encH, -I, and -J and the enzyme homologues of primary metabolism. Disruption of the benzoate-CoA ligase encN gene did not perturb enterocin production, however, demonstrating that encN is extraneous and that benzoic acid is not a pathway intermediate. EncN rather serves as a substitute pathway for utilizing exogenous benzoic acid. These experiments provide further support that benzoyl-CoA is formed in a novel bacterial pathway that resembles the eukaryotic assembly of benzoyl-CoA from phenylalanine via a β-oxidative path. PMID:12511484

Amino Acid Substitutions Associated with Avian H5N6 Influenza A Virus Adaptation to Mice

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Chunmao Zhang

2017-09-01

Full Text Available At least 15 cases of human beings infected with H5N6 have been reported since 2014, of which at least nine were fatal. The highly pathogenic avian H5N6 influenza virus may pose a serious threat to both public health and the poultry industry. However, the molecular features promoting the adaptation of avian H5N6 influenza viruses to mammalian hosts is not well understood. Here, we sequentially passaged an avian H5N6 influenza A virus (A/Northern Shoveler/Ningxia/488-53/2015 10 times in mice to identify the adaptive amino acid substitutions that confer enhanced virulence to H5N6 in mammals. The 1st and 10th passages of the mouse-adapted H5N6 viruses were named P1 and P10, respectively. P1 and P10 displayed higher pathogenicity in mice than their parent strain. P10 showed significantly higher replication capability in vivo and could be detected in the brains of mice, whereas P1 displayed higher replication efficiency in their lungs but was not detectable in the brain. Similar to its parent strain, P10 remained no transmissible between guinea pigs. Using genome sequencing and alignment, multiple amino acid substitutions, including PB2 E627K, PB2 T23I, PA T97I, and HA R239H, were found in the adaptation of H5N6 to mice. In summary, we identified amino acid changes that are associated with H5N6 adaptation to mice.

Synthesis and HPLC evaluation of carboxylic acid phases on a hydride surface.

Science.gov (United States)

Pesek, Joseph J; Matyska, Maria T; Gangakhedkar, Surekha; Siddiq, Rukhsana

2006-04-01

Three organic moieties containing carboxylic acid functional groups are attached to a particulate silica surface through silanization/hydrosilation. Two compounds (undecylenic acid and 10-undecynoic acid) have 11 carbon chains and the other is a five-carbon acid (pentenoic acid). Bonding is confirmed through carbon elemental analysis, diffuse reflectance infrared fourier transform spectroscopy, and carbon-13 and silicon-29 CP-MAS NMR spectroscopy. The bonded phases are tested by HPLC using PTH amino acids, nucleic acids, theophylline-related compounds, anilines, benzoic acid compounds, choline, and tobramycin. The latter two compounds are used to investigate the aqueous normal phase properties of the three bonded materials.

Hydroxyl and methoxyl derivatives of benzylglucosinolate in Lepidium densiflorum with hydrolysis to isothiocyanates and non-isothiocyanate products

DEFF Research Database (Denmark)

Pagnotta, Eleonora; Agerbirk, Niels; Olsen, Carl Erik

2017-01-01

A system of benzylic glucosinolates was found and characterized in common pepperweed, Lepidium densiflorum Schrad. The major glucosinolate was the novel 4-hydroxy-3,5-dimethoxybenzylglucosinolate (3,5-dimethoxysinalbin), present at high levels in seeds, leaves, and roots. Medium......-level glucosinolates were 3,4-dimethoxybenzylglucosinolate and 3,4,5-trimethoxybenzylglucosinolate. Minor glucosinolates included benzylglucosinolate, 3-hydroxy- and 3-methoxybenzylglucosinolate, 4-hydroxybenzylglucosinolate (sinalbin), the novel 4-hydroxy-3-methoxybenzylglucosinolate (3-methoxysinalbin), and indole......-type glucosinolates. A biosynthetic connection is suggested. NMR, UV, and ion trap MS/MS spectral data are reported, showing contrasting MS fragmentation of p-hydroxyls and p-methoxyls. Additional investigations by GC-MS focused on glucosinolate hydrolysis products. Whereas glucosinolates generally yielded...

How to Plant Apple Trees to Reduce Replant Disease in Apple Orchard: A Study on the Phenolic Acid of the Replanted Apple Orchard.

Directory of Open Access Journals (Sweden)

Chengmiao Yin

Full Text Available Apple replant disease (ARD is an important problem in the production of apple. The phenolic acid is one of the causes of ARD. How phenolic acid affects the ARD was not well known. In this study, we analyzed the type, concentration and annual dynamic variation of phenolic acid in soil from three replanted apple orchards using an accelerated solvent extraction system with high performance liquid chromatography (ASE-HPLC. We found that the type and concentration of phenolic acid were significantly differed among different seasons, different sampling positions and different soil layers. Major types of phenolic acid in three replanted apple orchards were phlorizin, benzoic acid and vanillic aldehyde. The concentration of phenolic acid was highest in the soil of the previous tree holes and it was increased from the spring to autumn. Moreover, phenolic acid was primarily distributed in 30-60 cm soil layer in the autumn, while it was most abundant in 0-30 cm soil layer in the spring. Our results suggest that phlorizin, benzoic acid and vanillic aldehyde may be the key phenolic acid that brought about ARD in the replanted apple orchard.

Commercial formalin substitutes for histopathology

DEFF Research Database (Denmark)

Prentø, P; Lyon, H

1997-01-01

We compared the performance of six commercial fixatives proposed to be formalin substitutes with the performance of buffered formalin, Clarke's ethanol-acetic acid, and ethanol, using rat liver, small intestine, and kidney. We investigated the rate of penetration, mode of fixation, extent of prot...... was obtained by combining formalin fixation with antigen retrieval. We conclude that none of the proposed commercial substitutes for buffered formalin are adequate for critical histology or histopathology....

Effects of microwave power and irradiation time on pectin extraction from watermelon rinds (Citrullus lanatus) with acetic acid using microwave assisted extraction method

Science.gov (United States)

Sari, A. M.; Ishartani, D.; Dewanty, P. S.

2018-01-01

The aims of this research are to study the effect of microwave power (119.7 W, 199.5 W and 279.3 W) and irradiation time (6, 9 and 12 min) on pectin extraction by using Microwave Assisted Extraction (MAE) with acetic acid and to do a preliminary characterization of pectin from watermelon rinds. A randomized factorial design with two factors was used to determine the effect of microwave power and processing time on the yield, equivalent weight, degree of methoxylation (DM), galacturonic acid content (GA) and the degree of esterification (DE) of extracted pectin. The results showed that extracted pectin from watermelon rinds using MAE method have yield ranged from 3.925% to 5.766%, with equivalent weight ranged from 1249.702 to 2007.756. Extracted pectin have a DM value ranged from 3.89% to 10.81%. Galacturonic acid content that meets with IPPA standard resulted from extraction condition of 279.3-watt microwave power for 9 min and 12 min. The degree of esterification (DE) value ranged from 56.86% to 85.76%, and this value exhibited a relatively high methoxyl pectin (>50%). The best pectin properties was obtained at a microwave power of 279.3 watts for 12 min.

Thiolated citrus low-methoxyl pectin: Synthesis, characterization and rheological and oxidation-responsive gelling properties.

Science.gov (United States)

Chen, Jinfeng; Ye, Fayin; Zhou, Yun; Zhao, Guohua

2018-02-01

In the present study, citrus low-methoxyl pectin was modified by conjugating cysteine via amide bonds, and the resultant polymer (CYS-PEC) was characterized. CYS-PEC conjugates with thiol contents varying from 77.8μmol/g to 296μmol/g were synthesized, and the successful conjugation was evidenced by elemental, and FT-IR analyses. The sulfur in CYS-PEC is predominately in the thiol form, with a minor fraction forming disulfide bonds (∼15%), which occur when thiol/disulfide interchange interrupts the intended thiolation. Both native and modified pectin dispersions exhibited strong pseudoplastic properties, and the frequency sweeps revealed them to be dispersions containing microgel particles. Dynamic viscoelastic analysis was used to determine the oxidation-response gelling capacities of polymer dispersions containing H 2 O 2 , especially those that are highly thiolated and have cross-linked gel properties. For oxidation-induced CYS-PEC gels, their gelation time, hardness, viscosity and elastic moduli and swelling-disintegration ratio are dependent on the thiol group content, H 2 O 2 concentration and polymer concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

Energy Technology Data Exchange (ETDEWEB)

Agustia, Yuda Virgantara, E-mail: yuda.mechanical.engineer@student.uns.ac.id; Suyitno,, E-mail: suyitno@uns.ac.id; Sutanto, Bayu, E-mail: bayu.sutanto@student.uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Arifin, Zainal, E-mail: zainal-a@uns.ac.id [Department of Mechanical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta (Indonesia); Department of Mechanical Engineering, Brawijaya University, Malang (Indonesia)

2016-03-29

The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E{sub HOMO} and E{sub LUMO} was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E{sub red} = −0.37V, E{sub LUMO} = −4.28 eV, E{sub ox} = 1.15V, E{sub HOMO} = −5.83 eV, and E{sub band} {sub gap} = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

Actions of four organic acids in radix isatidis on endotoxin-neutralization investigated by kinetic turbidimetric assay.

Science.gov (United States)

Ma, Li; He, Ying-jun; Li, You; Gong, Mu-xin

2012-06-01

To investigate anti-endotoxin action of four OAs reacted with endotoxin by the LAL assay with KTA. Using a incubating kinetic tube reader and kinetic turbidimetric assay (KTA), the concentration-response time curve of endotoxin reacted with limulus amebocyte lysate (LAL) at 37 degrees C were obtained and the action of four organic acids (OAs) on it were investigated. The four OAs were benzoic acid, salicylic acid, syringic acid and 2-amino-benzoic acid from Radix isatidis. Meanwhile, the temperature variation caused by endotoxin with the four OAs was studied by the rabbit pyrogen test (RPT). It was showed that a low concentration (1 mg/mL) of the four OAs had a little effect of anti-endotoxin, and when the concentrations of the four OAs were 30 mg/mL, the endotoxin was neutralized completely. The relationships between the concentrations of endotoxin and the OAs were all linear with correlation coefficients of greater than 0.9995, indicating that the four OAs all had strong anti-endotoxin action, while syringic acid had the strongest action among the four OAs with IC50 of 12.84 mg/mL. The investigations of KTA agreed well with the results obtained by means of RPT.

Substitution of aspartic acid-686 by histidine or asparagine in the human androgen receptor leads to a functionally inactive protein with altered hormone-binding characteristics

NARCIS (Netherlands)

Ris-Stalpers, C.; Trifiro, M. A.; Kuiper, G. G.; Jenster, G.; Romalo, G.; Sai, T.; van Rooij, H. C.; Kaufman, M.; Rosenfield, R. L.; Liao, S.

1991-01-01

We have identified two different single nucleotide alterations in codon 686 (GAC; aspartic acid) in exon 4 of the human androgen receptor gene in three unrelated families with the complete form of androgen insensitivity. One mutation (G----C) results in an aspartic acid----histidine substitution

Metal-Free, Site-Selective Peptide Modification by Conversion of "Customizable" Units into β-Substituted Dehydroamino Acids.

Science.gov (United States)

Saavedra, Carlos J; Hernández, Dácil; Boto, Alicia

2018-01-12

Our site-selective modification of serine or threonine units in peptides allows the generation of β-substituted dehydroamino acids, which increase peptide resistance to hydrolysis and may improve their biological properties. Both the terminal and internal positions can be modified, and different customizable units can be activated separately. Remarkably, high Z selectivity is achieved, even at internal positions. The conversion involves a one-pot oxidative radical scission/phosphorylation process by using the low-toxicity (diacetoxyiodo)benzene/iodine system as the scission reagent. The resulting α-amino phosphonates undergo a Horner-Wadsworth-Emmons reaction to produce the dehydroamino acid derivatives (in a Z/E ratio of usually >98:2) under mild and metal-free conditions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yeast allosteric chorismate mutase is locked in the activated state by a single amino acid substitution

International Nuclear Information System (INIS)

Schmidheini, T.; Moesch, H.U.; Braus, G.; Evans, J.N.S.

1990-01-01

Chorismate mutase, a branch-point enzyme in the aromatic amino acid pathway of Saccharomyces cerevisiae, and also a mutant chorismate mutase with a single amino acid substitution in the C-terminal part of the protein have been purified approximately 20-fold and 64-fold from overproducing strains, respectively. The wild-type enzyme is activated by tryptophan and subject to feedback inhibition by tyrosine, whereas the mutant enzyme does not respond to activation by tryptophan nor inhibition by tyrosine. Both enzymes are dimers consisting of two identical subunits of M r 30,000, each one capable of binding one substrate and one activator molecule. Each subunit of the wild-type enzyme also binds one inhibitor molecule, whereas the mutant enzyme lost this ability. The enzyme reaction was observed by 1 H NMR and shows a direct and irreversible conversion of chorismate to prephenate without the accumulation of any enzyme-free intermediates. The kinetic data of the wild-type chorismate mutase show positive cooperativity toward the substrate with a Hill coefficient of 1.71 and a [S] 0.5 value of 4.0 mM. In the presence of the activator tryptophan, the cooperativity is lost. The enzyme has an [S] 0.5 value of 1.2 mM in the presence of 10 μM tryptophan and an increased [S] 0.5 value of 8.6 mM in the presence of 300 μM tyrosine. In the mutant enzyme, a loss of the cooperativity was observed, and [S] 0.5 was reduced to 1.0 mM. This enzyme is therefore locked in the activated state by a single amino acid substitution

Separation and determination of some carboxylic acids by capillary electrophoresis

International Nuclear Information System (INIS)

Sladkov, V.; Fourest, B.

2006-01-01

Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

Separation and determination of some carboxylic acids by capillary electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Sladkov, V.; Fourest, B

2006-07-01

Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

Inconsistent Distances in Substitution Matrices can be Avoided by Properly Handling Hydrophobic Residues

Directory of Open Access Journals (Sweden)

J. Baussand

2008-01-01

Full Text Available The adequacy of substitution matrices to model evolutionary relationships between amino acid sequences can be numerically evaluated by checking the mathematical property of triangle inequality for all triplets of residues. By converting substitution scores into distances, one can verify that a direct path between two amino acids is shorter than a path passing through a third amino acid in the amino acid space modeled by the matrix. If the triangle inequality is not verified, the intuition is that the evolutionary signal is not well modeled by the matrix, that the space is locally inconsistent and that the matrix construction was probably based on insufficient biological data. Previous analysis on several substitution matrices revealed that the number of triplets violating the triangle inequality increases with sequence divergence. Here, we compare matrices which are dedicated to the alignment of highly divergent proteins. The triangle inequality is tested on several classical substitution matrices as well as in a pair of “complementary” substitution matrices recording the evolutionary pressures inside and outside hydrophobic blocks in protein sequences. The analysis proves the crucial role of hydrophobic residues in substitution matrices dedicated to the alignment of distantly related proteins.

The application of hydrogen-palladium electrode for potentiometric acid-base determinations in tetrahydrofuran

Directory of Open Access Journals (Sweden)

Jokić Anja B.

2013-01-01

Full Text Available The application of the hydrogen-palladium electrode (H2/Pd as the indicator electrode for the determination of relative acidity scale (Es, mV of tetrahydrofuran (THF and the potentiometric titrations of acids in this solvent was investigated. The relative acidity scale tetrahydrofuran was determined from the difference half-neutralization potentials of perchloric acid and tetrabutylammonium hydroxide (TBAH, which were measured by using both H2/Pd-SCE and glass-SCE electrode pairs. The experimentally obtained value of Es scale THF with a H2/Pd-SCE electrode pair was 1155 mV, and those obtained with glass-SCE electrode pair 880 mV. By using a H2/Pd indicator electrode, the individual acids (benzoic acid, palmitic acid, maleic acid, acetyl acetone, α-naphthol and two component acid mixtures (benzoic acid + α-naphthol, palmitic acid + α-naphthol, maleic acid + α-naphthol and maleic acid + ftalic acid were titrated with a standard solution of TBAH. In addition, sodium methylate and potassium hydroxide proved to be very suitable titrating agents for titrating of the individual acids and the acids in mixtures, respectively. The relative error of the determination of acids in mixture was less than 3%. The results are in agreement with those obtained by a conventional glass electrode. The advantages of H2/Pd electrode over a glass electrode in potentiometric acid-base determinations in tetrahydrofuran lie in the following: this electrode gives wider relative acidity scale THF, higher the potential jumps at the titration end-point and relatively fast response time; furthermore, it is very durable, simple to prepare and can be used in the titrations of small volumes. [Projekat Ministarstva nauke Republike Srbije, br.172051

Substitution determination of Fmoc‐substituted resins at different wavelengths

Science.gov (United States)

Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

2017-01-01

In solid‐phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc‐substituted resins, substitution determination is often performed by suspending the Fmoc‐protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene–piperidine adduct that is quantified by ultraviolet–visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene–piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert–Beer's law, together with the substance‐specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol−1 cm−1 and 8100 l mol−1 cm−1 have been reported for the dibenzofulvene–piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. PMID:28635051

Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β2,2 -Amino Acids.

Science.gov (United States)

Nascimento de Oliveira, Marllon; Arseniyadis, Stellios; Cossy, Janine

2018-04-03

We report here an unprecedented and highly enantioselective palladium-catalyzed allylic alkylation applied to 4-substituted isoxazolidin-5-ones. Ultimately, the process provides a straightforward access to β 2,2 -amino acids bearing an all-carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Control of Chemical Risks by Substitution of Harmful Substances

DEFF Research Database (Denmark)

Jacobsen, Thomas

1997-01-01

Substitution of volatile, organic solvents with non-volatile, low-toxic esters of fatty acids for cleaning purposes in offset printing has successfully been implemented in several European countries. Similar substitutions in other industrial cleaning processes seem possible, especially regarding...

Intake of dietary saturated fatty acids and risk of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition-Netherlands cohort: associations by types, sources of fatty acids and substitution by macronutrients.

Science.gov (United States)

Liu, Shengxin; van der Schouw, Yvonne T; Soedamah-Muthu, Sabita S; Spijkerman, Annemieke M W; Sluijs, Ivonne

2018-03-09

The association between dietary saturated fatty acids (SFA) intake and type 2 diabetes (T2D) remains unclear. This study aimed at investigating the association between SFA intake and T2D risk based on (1) individual SFA (differing in carbon chain length), (2) food sources of SFA and (3) the substituting macronutrients. 37,421 participants from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) cohort were included in this study. Baseline dietary intake was assessed by a validated food frequency questionnaire. T2D risks were estimated by Cox regression models adjusted for non-dietary and dietary covariates. 893 incident T2D cases were documented during 10.1-year follow-up. We observed no association between total SFA and T2D risk. Marginally inverse associations were found for lauric acid (HR per 1 SD of energy%, 95% CI 0.92, 0.85-0.99), myristic acid (0.89, 0.79-0.99), margaric acid (0.84, 0.73-0.97), odd-chain SFA (pentadecylic plus margaric acids; 0.88, 0.79-0.99), and cheese derived SFA (0.90, 0.83-0.98). Soft and liquid fats derived SFA was found related to higher T2D risk (1.08, 1.01-1.17). When substituting SFA by proteins, carbohydrates and polyunsaturated fatty acids, significantly higher risks of T2D were observed (HRs per 1 energy% ranging from 1.05 to 1.15). In this Dutch population, total SFA does not relate to T2D risk. Rather, the association may depend on the types and food sources of SFA. Cheese-derived SFA and individual SFA that are commonly found in cheese, were significantly related to lower T2D risks. We cannot exclude the higher T2D risks found for soft and liquid fats derived SFA and for substituting SFA with other macronutrients are influenced by residual confounding by trans fatty acids or limited intake variation in polyunsaturated fatty acids and vegetable protein.

Partial molar volumes of some drug and pro-drug substances in 1-octanol at T = 298.15 K

Energy Technology Data Exchange (ETDEWEB)

Manin, Alex N.; Shmukler, Liudmila E.; Safonova, Liubov P. [Institute of Solution Chemistry, Russian Academy of Sciences, 153045 Ivanovo (Russian Federation); Perlovich, German L., E-mail: glp@isc-ras.r [Institute of Solution Chemistry, Russian Academy of Sciences, 153045 Ivanovo (Russian Federation)

2010-03-15

The article deals with measuring the densities of phenol, acetanilide, benzamide, benzoic acid, phenacetin, i-(acetylamino)-benzoic acid, i-hydroxy-benzamide, and i-acetaminophen (where i = 1, 2, 3) in 1-octanol in the wide concentration interval at T = 298.15 K. It also concerns the evaluation of apparent molar volumes and partial molar volumes at infinite dilution, V{sub 2}{sup 0}-bar as well as comparative analysis of the free volumes per molecule in the octanolic solutions, V{sub 2}{sup free}, and in the crystal lattices, V{sub 2}{sup free} (cr), from the nature and position of the substitutes. Also described is the evaluation of the increments of V{sub 2}{sup 0}-bar andV{sub 2}{sup free} for the unsubstituted molecules and isomers and the methods to obtain partial molar volumes for various functional groups at infinite dilution in 1-octanol at T = 298.15 K. Also considered is the limiting partial molar volume of the solutes in terms of the scaled particle theory.

Substituent and structural effects on the kinetics of the reaction of N-(substituted phenylmethylene-m- and -p-aminobenzoic acids with diazodiphenylmethane

Directory of Open Access Journals (Sweden)

BRATISLAV Z. JOVANOVIC

2007-12-01

Full Text Available The rate constants for the reaction of twenty-two N-(substituted phenyl methylene-m- and -p-aminobenzoic acids with diazodiphenylmethane were determined in absolute ethanol at 30 °C. The effects of substituents on the reactivity of the investigated compounds were interpreted by correlation of the rate constants with LFER equations. The results of quantum mechanical calculations of the mole cular structure together with experimental results gave a better insight into the effects of structure on the transmission of electronic effects of the substituents. New σ constants for substituted benzylideneamino group were calculated.

Anodic oxidation of salicylic acid on BDD electrode: Variable effects and mechanisms of degradation

Energy Technology Data Exchange (ETDEWEB)

Rabaaoui, Nejmeddine, E-mail: chimie_tunisie@yahoo.fr [Faculte des Sciences de Sfax, Departement de Chimie, 3038 Sfax (Tunisia); Allagui, Mohamed Salah [Faculte des Sciences de Gafsa, Campus Universitaire Sidi Ahmed Zarrouk, 2112 Gafsa (Tunisia)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Oxidation with BDD is a powerful electrochemical method able to mineralize. Black-Right-Pointing-Pointer SA is oxidized to aromatic compounds then CO{sub 2} and H{sub 2}O. Black-Right-Pointing-Pointer Polymeric intermediate products were formed. - Abstract: The degradation of 100 mL of solution with salicylic acid (SA) in the pH range 3.0-10.0 has been studied by anodic oxidation in a cell with a boron-doped diamond (BDD) anode and a stainless steel cathode, both of 3 cm{sup 2} area, by applying a current of 100, 300 and 450 mA at 25 Degree-Sign C. Completed mineralization is always achieved due to the great concentration of hydroxyl radical ({center_dot}OH) generated at the BDD surface. The mineralization rate increases with increasing applied current, but decreases when drug concentration rises from 200 mg L{sup -1}. Nevertheless, the pH effect was not significant. During oxidation it was observed that catechol, 2,5-dihydroxylated benzoic acid, 2,3-dihydroxylated benzoic acid and hydroquinone were formed as aromatic intermediates. In addition, ion-exclusion chromatography allowed the detection of fumaric, maleic, oxalic and formic as the ultimate carboxylic acid.

Synthesis and Biological Activity of Novel Amino Acid-(N'-Benzoyl Hydrazide and Amino Acid-(N'-Nicotinoyl Hydrazide Derivatives

Directory of Open Access Journals (Sweden)

Sherine N. Khattab

2005-09-01

Full Text Available The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-amino acids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-amino acid-(N`-benzoyl- and N- Boc-amino acid-(N`-nicotinoyl hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl- methylene]-N-methyl-methanaminium hexafluorophosphate N-oxide (HATU as coupling reagent. The antimicrobial activity of the Cu and Cd complexes of the designed compounds was tested. The products were deprotected affording the corresponding amino acid-(N`-benzoyl hydrazide hydrochloride salts (7a-7e and amino acid-(N`- nicotinoyl hydrazide hydrochloride salts (8a-8e. These compounds and their Cu and Cd complexes were also tested for their antimicrobial activity. Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli.

Evaluation of accelerated UV and thermal testing for benzene formation in beverages containing benzoate and ascorbic acid.

Science.gov (United States)

Nyman, Patricia J; Wamer, Wayne G; Begley, Timothy H; Diachenko, Gregory W; Perfetti, Gracia A

2010-04-01

Under certain conditions, benzene can form in beverages containing benzoic and ascorbic acids. The American Beverage Assn. (ABA) has published guidelines to help manufacturers mitigate benzene formation in beverages. These guidelines recommend accelerated testing conditions to test product formulations, because exposure to ultraviolet (UV) light and elevated temperature over the shelf life of the beverage may result in benzene formation in products containing benzoic and ascorbic acids. In this study, the effects of UVA exposure on benzene formation were determined. Benzene formation was examined for samples contained in UV stabilized and non-UV stabilized packaging. Additionally, the usefulness of accelerated thermal testing to simulate end of shelf-life benzene formation was evaluated for samples containing either benzoic or ascorbic acid, or both. The 24 h studies showed that under intense UVA light benzene levels increased by as much as 53% in model solutions stored in non-UV stabilized bottles, whereas the use of UV stabilized polyethylene terephthalate bottles reduced benzene formation by about 13% relative to the non-UV stabilized bottles. Similar trends were observed for the 7 d study. Retail beverages and positive and negative controls were used to study the accelerated thermal testing conditions. The amount of benzene found in the positive controls and cranberry juice suggests that testing at 40 degrees C for 14 d may more reliably simulate end of shelf-life benzene formation in beverages. Except for cranberry juice, retail beverages were not found to contain detectable amounts of benzene (<0.05 ng/g) at the end of their shelf lives.

Dissociation and homoconjugation equilibria of some acids and bases in N,N-dimethylformamide.

Science.gov (United States)

Roletto, E; Vanni, A

1977-01-01

The following monoprotic acids have been studied in N,N-dimethylformamide (DMF): p-toluenesulphonic acid; 2,6-dichlorobenzoic acid; 2,5-dichlorophenol; the anilinium ion; the N-methyl-anilinium ion. The first dissociation step of malonic and succinic acids has also been studied. Dissociation and homoconjugation constants have been determined potentiometrically, at 25 degrees , in buffer solutions containing either the acid and its tetraethylammonium salt or the base and its picrate. Homoconjugation equilibria between unchanged acid and univalent conjugate base have been found not only for benzoic acid and phenol derivatives, but also between undissociated diprotic carboxylic acids and the corresponding monoanions, which are strongly intramolecularly hydrogen-bonded. Results are discussed with reference to previously published values.

Determination and prediction of octanol-air partition coefficients of hydroxylated and methoxylated polybrominated diphenyl ethers.

Science.gov (United States)

Zhao, Hongxia; Xie, Qing; Tan, Feng; Chen, Jingwen; Quan, Xie; Qu, Baocheng; Zhang, Xin; Li, Xiaona

2010-07-01

The octanol-air partition coefficient (K(OA)) of 19 hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and 10 methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were measured as a function of temperature using a gas chromatographic retention time technique. At room temperature (298.15K), log K(OA) ranged from 8.30 for monobrominated OH/MeO-PBDEs to 13.29 for hexabrominated OH/MeO-PBDEs. The internal energies of phase change from octanol to air (Delta(OA)U) for 29 OH/MeO-PBDE congeners ranged from 72 to 126 kJ mol(-1). Using partial least-squares (PLS) analysis, a statistically quantitative structure-property relationship (QSPR) model for logK(OA) of OH/MeO-PBDE congeners was developed based on the 16 fundamental quantum chemical descriptors computed by PM3 Hamiltonian, for which the Q(cum)(2) was about 0.937. The molecular weight (Mw) and energy of the lowest unoccupied molecular orbital (E(LUMO)) were found to be main factors governing the log K(OA). 2010 Elsevier Ltd. All rights reserved.

Identification of two critical amino acid residues of the severe acute respiratory syndrome coronavirus spike protein for its variation in zoonotic tropism transition via a double substitution strategy.

Science.gov (United States)

Qu, Xiu-Xia; Hao, Pei; Song, Xi-Jun; Jiang, Si-Ming; Liu, Yan-Xia; Wang, Pei-Gang; Rao, Xi; Song, Huai-Dong; Wang, Sheng-Yue; Zuo, Yu; Zheng, Ai-Hua; Luo, Min; Wang, Hua-Lin; Deng, Fei; Wang, Han-Zhong; Hu, Zhi-Hong; Ding, Ming-Xiao; Zhao, Guo-Ping; Deng, Hong-Kui

2005-08-19

Severe acute respiratory syndrome coronavirus (SARS-CoV) is a recently identified human coronavirus. The extremely high homology of the viral genomic sequences between the viruses isolated from human (huSARS-CoV) and those of palm civet origin (pcSARS-CoV) suggested possible palm civet-to-human transmission. Genetic analysis revealed that the spike (S) protein of pcSARS-CoV and huSARS-CoV was subjected to the strongest positive selection pressure during transmission, and there were six amino acid residues within the receptor-binding domain of the S protein being potentially important for SARS progression and tropism. Using the single-round infection assay, we found that a two-amino acid substitution (N479K/T487S) of a huSARS-CoV for those of pcSARS-CoV almost abolished its infection of human cells expressing the SARS-CoV receptor ACE2 but no effect upon the infection of mouse ACE2 cells. Although single substitution of these two residues had no effects on the infectivity of huSARS-CoV, these recombinant S proteins bound to human ACE2 with different levels of reduced affinity, and the two-amino acid-substituted S protein showed extremely low affinity. On the contrary, substitution of these two amino acid residues of pcSARS-CoV for those of huSRAS-CoV made pcSARS-CoV capable of infecting human ACE2-expressing cells. These results suggest that amino acid residues at position 479 and 487 of the S protein are important determinants for SARS-CoV tropism and animal-to-human transmission.

Identification of single amino acid substitutions (SAAS) in neuraminidase from influenza a virus (H1N1) via mass spectrometry analysis coupled with de novo peptide sequencing.

Science.gov (United States)

Peng, Qisheng; Wang, Zijian; Wu, Donglin; Li, Xiaoou; Liu, Xiaofeng; Sun, Wanchun; Liu, Ning

2016-08-01

Amino acid substitutions in the neuraminidase of the influenza virus are the main cause of the emergence of resistance to zanamivir or oseltamivir during seasonal influenza treatment; they are the result of non-synonymous mutations in the viral genome that can be successfully detected by polymer chain reaction (PCR)-based approaches. There is always an urgent need to detect variation in amino acid sequences directly at the protein level. Mass spectrometry coupled with de novo sequencing has been explored as an alternative and straightforward strategy for detecting amino acid substitutions, as well - this approach is the primary focus of the present study. Influenza virus (A/Puerto Rico/8/1934 H1N1) propagated in embryonated chicken eggs was purified by ultracentrifugation, followed by PNGase F treatment. The deglycosylated virion was lysed and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The gel band corresponding to neuraminidase was picked up and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. LC-MS/MS analyses, coupled with manual de novo sequencing, allowed the determination of three amino acid substitutions: R346K, S349 N, and S370I/L, in the neuraminidase from the influenza virus (A/Puerto Rico/8/1934 H1N1), which were located in three mutated peptides of the neuraminidase: YGNGVWIGK, TKNHSSR, and PNGWTETDI/LK, respectively. We found that the amino acid substitutions in the proteins of RNA viruses (including influenza A virus) resulting from non-synonymous gene mutations can indeed be directly analyzed via mass spectrometry, and that manual interpretation of the MS/MS data may be beneficial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Substitution determination of Fmoc-substituted resins at different wavelengths.

Science.gov (United States)

Eissler, Stefan; Kley, Markus; Bächle, Dirk; Loidl, Günther; Meier, Thomas; Samson, Daniel

2017-10-01

In solid-phase peptide synthesis, the nominal batch size is calculated using the starting resin substitution and the mass of the starting resin. The starting resin substitution constitutes the basis for the calculation of a whole set of important process parameters, such as the number of amino acid derivative equivalents. For Fmoc-substituted resins, substitution determination is often performed by suspending the Fmoc-protected starting resin in 20% (v/v) piperidine in DMF to generate the dibenzofulvene-piperidine adduct that is quantified by ultraviolet-visible spectroscopy. The spectrometric measurement is performed at the maximum absorption wavelength of the dibenzofulvene-piperidine adduct, that is, at 301.0 nm. The recorded absorption value, the resin weight and the volume are entered into an equation derived from Lambert-Beer's law, together with the substance-specific molar absorption coefficient at 301.0 nm, in order to calculate the nominal substitution. To our knowledge, molar absorption coefficients between 7100 l mol -1  cm -1 and 8100 l mol -1  cm -1 have been reported for the dibenzofulvene-piperidine adduct at 301.0 nm. Depending on the applied value, the nominal batch size may differ up to 14%. In this publication, a determination of the molar absorption coefficients at 301.0 and 289.8 nm is reported. Furthermore, proof is given that by measuring the absorption at 289.8 nm the impact of wavelength accuracy is reduced. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. © 2017 The Authors Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

Blocking of proteolytic processing and deletion of glycosaminoglycan side chain of mouse DMP1 by substituting critical amino acid residues.

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Peng, Tao; Huang, Bingzhen; Sun, Yao; Lu, Yongbo; Bonewald, Lynda; Chen, Shuo; Butler, William T; Feng, Jerry Q; D'Souza, Rena N; Qin, Chunlin

2009-01-01

Dentin matrix protein 1 (DMP1) is present in the extracellular matrix (ECM) of dentin and bone as processed NH(2)- and COOH-terminal fragments, resulting from proteolytic cleavage at the NH(2) termini of 4 aspartic acid residues during rat DMP1 processing. One cleavage site residue, Asp(181) (corresponding to Asp(197) of mouse DMP1), and its flanking region are highly conserved across species. We speculate that cleavage at the NH(2) terminus of Asp(197) of mouse DMP1 represents an initial, first-step scission in the whole cascade of proteolytic processing. To test if Asp(197) is critical for initiating the proteolytic processing of mouse DMP1, we substituted Asp(197) with Ala(197) by mutating the corresponding nucleotides of mouse cDNA that encode this amino acid residue. This mutant DMP1 cDNA was cloned into a pcDNA3.1 vector. Data from transfection experiments indicated that this single substitution blocked the proteolytic processing of mouse DMP1 in HEK-293 cells, indicating that cleavage at the NH(2) terminus of Asp(197) is essential for exposing other cleavage sites for the conversion of DMP1 to its fragments. The NH(2)-terminal fragment of DMP1 occurs as a proteoglycan form (DMP1-PG) that contains a glycosaminoglycan (GAG) chain. Previously, we showed that a GAG chain is linked to Ser(74) in rat DMP1 (Ser(89) in mouse DMP1). To confirm that mouse DMP1-PG possesses a single GAG chain attached to Ser(89), we substituted Ser(89) by Gly(89). Data from transfection analysis indicated that this substitution completely prevented formation of the GAG-containing form, confirming that DMP1-PG contains a single GAG chain attached to Ser(89) in mouse DMP1. Copyright 2008 S. Karger AG, Basel.

Effect of acidity on the energy level of curcumin dye extracted from Curcuma longa L

International Nuclear Information System (INIS)

Agustia, Yuda Virgantara; Suyitno,; Sutanto, Bayu; Arifin, Zainal

2016-01-01

The purpose of this research is to investigate the effect of acidity on the energy level of curcumin dye. The natural dye, curcumin, was synthesized from Curcuma longa L. using a simple extraction technique. The purification of curcumin dye was conducted in a column of chromatography and its characteristics were studied. Next, the purified curcumin dye was added by benzoic acids until various acidities of 3.0, 3.5, 4.0, 4.5, and 5.0. The absorbance spectra and the functionality groups found in the dyes were detected by ultraviolet-visible spectroscopy and Fourier-transform infrared spectroscopy, respectively. Meanwhile, the energy level of the dyes, E_H_O_M_O and E_L_U_M_O was measured by cyclic voltammetry. The best energy level of curcumin dye was achieved at pH 3.5 where E_r_e_d = −0.37V, E_L_U_M_O = −4.28 eV, E_o_x = 1.15V, E_H_O_M_O = −5.83 eV, and E_b_a_n_d _g_a_p = 1.55 eV. Therefore, the purified curcumin dye added by benzoic acid was promising for sensitizing the dye-sensitized solar cells.

Metabolomics Analysis Reveals Specific Novel Tetrapeptide and Potential Anti-Inflammatory Metabolites in Pathogenic Aspergillus species.

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Lee, Kim-Chung; Tam, Emily W T; Lo, Ka-Ching; Tsang, Alan K L; Lau, Candy C Y; To, Kelvin K W; Chan, Jasper F W; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

2015-06-17

Infections related to Aspergillus species have emerged to become an important focus in infectious diseases, as a result of the increasing use of immunosuppressive agents and high fatality associated with invasive aspergillosis. However, laboratory diagnosis of Aspergillus infections remains difficult. In this study, by comparing the metabolomic profiles of the culture supernatants of 30 strains of six pathogenic Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, A. nomius and A. tamarii) and 31 strains of 10 non-Aspergillus fungi, eight compounds present in all strains of the six Aspergillus species but not in any strain of the non-Aspergillus fungi were observed. One of the eight compounds, Leu-Glu-Leu-Glu, is a novel tetrapeptide and represents the first linear tetrapeptide observed in Aspergillus species, which we propose to be named aspergitide. Two other closely related Aspergillus-specific compounds, hydroxy-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid, may possess anti-inflammatory properties, as 2-(sulfooxy)benzoic acid possesses a structure similar to those of aspirin [2-(acetoxy)benzoic acid] and salicylic acid (2-hydroxybenzoic acid). Further studies to examine the potentials of these Aspergillus-specific compounds for laboratory diagnosis of aspergillosis are warranted and further experiments will reveal whether Leu-Glu-Leu-Glu, hydroxy-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid are virulent factors of the pathogenic Aspergillus species.

Crystal structure of (E-4-{2-[4-(allyloxyphenyl]diazenyl}benzoic acid

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Md. Lutfor Rahman

2014-12-01

Full Text Available The title compound, C16H14N2O3, has an E conformation about the azobenzene [—N=N– = 1.2481 (16 Å] linkage. The benzene rings are almost coplanar [dihedral angle = 1.36 (7°]. The O atoms of the carboxylic acid group are disordered over two sets of sites and were refined with an occupancy ratio of 0.5:0.5. The two disordered components of the carboxylic acid group make dihedral angles of 1.5 (14 and 3.8 (12° with the benzene ring to which they are attached. In the crystal, molecules are linked via pairs of O—H...O hydrogen bonds, forming inversion dimers. The dimers are connected via C—H...O hydrogen bonds, forming ribbons lying parallel to [120]. These ribbons are linked via C—H...π interactions, forming slabs parallel to (001.

用清洁生产理念优化苯甲醇和苯甲酸的合成实验%Experiment of Synthesis Optimization for Benzyl Alcohol and Benzoic Acid by Stratagem of Clean Production

Institute of Scientific and Technical Information of China (English)

鹿桂芳; 赵喜芝; 王珩

2009-01-01

Preparing benzyl alcohol and benzoic acid by benzyalde is an important experiment in organic chemistry experiment teaching in colleges. But in conventional experiment some problem appears including great consumption of alkali and acid as well as pollution of benzene and hydrogen chloride on the laboratory. In the highlight of clean production such as source controlling, pollution reduction and efficiency enhancement, the parameters of traditional experiment were optimized for the purpose of reducing the pollution of laboratory. The stratagem of clean production may direct a new way for students' life.%以苯甲醛为原料制备苯甲醇与苯甲酸是高校有机化学实验教学中的一个重要实验,但在传统实验中,存在原料用量大,苯、氯化氢污染实验室环境等问题.文章利用清洁生产从源头控制、减污增效的思想,对本实验的传统参数进行了优化,从而减轻对实验室的污染.并在该思想的引领下,使学生了解清洁生产可从身边的事做起.

Molecular characterization of amino acid deletion in VP1 (1D) protein and novel amino acid substitutions in 3D polymerase protein of foot and mouth disease virus subtype A/Iran87.

Science.gov (United States)

Esmaelizad, Majid; Jelokhani-Niaraki, Saber; Hashemnejad, Khadije; Kamalzadeh, Morteza; Lotfi, Mohsen

2011-12-01

The nucleotide sequence of the VP1 (1D) and partial 3D polymerase (3D(pol)) coding regions of the foot and mouth disease virus (FMDV) vaccine strain A/Iran87, a highly passaged isolate (~150 passages), was determined and aligned with previously published FMDV serotype A sequences. Overall analysis of the amino acid substitutions revealed that the partial 3D(pol) coding region contained four amino acid alterations. Amino acid sequence comparison of the VP1 coding region of the field isolates revealed deletions in the highly passaged Iranian isolate (A/Iran87). The prominent G-H loop of the FMDV VP1 protein contains the conserved arginine-glycine-aspartic acid (RGD) tripeptide, which is a well-known ligand for a specific cell surface integrin. Despite losing the RGD sequence of the VP1 protein and an Asp(26)→Glu substitution in a beta sheet located within a small groove of the 3D(pol) protein, the virus grew in BHK 21 suspension cell cultures. Since this strain has been used as a vaccine strain, it may be inferred that the RGD deletion has no critical role in virus attachment to the cell during the initiation of infection. It is probable that this FMDV subtype can utilize other pathways for cell attachment.

Molecular Interaction between Lipoteichoic Acids and Lactobacillus delbrueckii Phages Depends on d-Alanyl and α-Glucose Substitution of Poly(Glycerophosphate) Backbones▿

Science.gov (United States)

Räisänen, Liisa; Draing, Christian; Pfitzenmaier, Markus; Schubert, Karin; Jaakonsaari, Tiina; von Aulock, Sonja; Hartung, Thomas; Alatossava, Tapani

2007-01-01

Lipoteichoic acids (LTAs) have been shown to act as bacterial counterparts to the receptor binding proteins of LL-H, LL-H host range mutant LL-H-a21, and JCL1032. Here we have used LTAs purified by hydrophobic interaction chromatography from different phage-resistant and -sensitive strains of Lactobacillus delbrueckii subsp. lactis. Nuclear magnetic resonance analyses revealed variation in the degree of α-glucosyl and d-alanyl substitution of the 1,3-linked poly(glycerophosphate) LTAs between the phage-sensitive and phage-resistant strains. Inactivation of phages was less effective if there was a high level of d-alanine residues in the LTA backbones. Prior incubation of the LTAs with α-glucose-specific lectin inhibited the LL-H phage inactivation. The overall level of decoration or the specific spatial combination of α-glucosyl-substituted, d-alanyl-substituted, and nonsubstituted glycerol residues may also affect phage adsorption. PMID:17416656

Pasture, multi-enzymes, benzoic acid and essential oils positively influence performance, intestinal organ weight and egg quality in free-range laying hens.

Science.gov (United States)

Iqbal, Z; Roberts, J; Perez-Maldonado, R A; Goodarzi Boroojeni, F; Swick, R A; Ruhnke, I

2018-04-01

1. The objective of this study was to investigate the effect of range type, multi-enzyme applications, and a combination of benzoic acid (BA) and essential oils (EO) on the productive performance, organ weight and egg quality of free-range laying hens. 2. Three hundred laying hens were evaluated for the short-term (6 weeks) and long-term (12 weeks) effects of range type (G = no pasture, P = pasture) and feed additives (T1 = control; T2 = betaglucanase/pectinase/protease; T3 = BA/EO). Body weight, feed intake (FI), feed conversion ratio (FCR), egg production (EP), digestive organ weight, and egg quality (EQ) were evaluated. Data were analysed using SPSS 2.2 in a 2×2×3 factorial arrangement. 3. Hens that ranged on pasture were significantly heavier (2043 g vs. 1996 g; p ranged on gravel. Hens fed T2 were significantly heavier (2050 g) compared to hens fed T1 (2005 g) or T3 (2008 g). Organ weights (gizzard, liver and pancreas) were significantly heavier in hens ranged on pasture (16.8 g/kg BW, 22.3 g/kg BW and 1.89 g/kg BW, respectively) compared to hens ranged on gravel (14.2 g/kg BW, 21.7 g/kg BW and 1.83 g/kg BW, respectively). Over time, body weight (1970-2070 g; p < 0.001) and egg weight (59.5-62.8 g; p < 0.001) increased, FI (123-120 g; p = 0.024) was reduced and FCR (2.36-2.10; p = 0.002) improved 4. In conclusion, hens housed on pasture and fed multi-enzyme supplemented diets had significantly heavier body weight and produced heavier eggs with darker yolk colour. Pasture intake and enzyme supplementation increased digestive organ weight significantly.

Canine distemper virus neutralization activity is low in human serum and it is sensitive to an amino acid substitution in the hemagglutinin protein.

Science.gov (United States)

Zhang, Xinsheng; Wallace, Olivia L; Domi, Arban; Wright, Kevin J; Driscoll, Jonathan; Anzala, Omu; Sanders, Eduard J; Kamali, Anatoli; Karita, Etienne; Allen, Susan; Fast, Pat; Gilmour, Jill; Price, Matt A; Parks, Christopher L

2015-08-01

Serum was analyzed from 146 healthy adult volunteers in eastern Africa to evaluate measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb) prevalence and potency. MV plaque reduction neutralization test (PRNT) results indicated that all sera were positive for MV nAbs. Furthermore, the 50% neutralizing dose (ND50) for the majority of sera corresponded to antibody titers induced by MV vaccination. CDV nAbs titers were low and generally were detected in sera with high MV nAb titers. A mutant CDV was generated that was less sensitive to neutralization by human serum. The mutant virus genome had 10 nucleotide substitutions, which coded for single amino acid substitutions in the fusion (F) and hemagglutinin (H) glycoproteins and two substitutions in the large polymerase (L) protein. The H substitution occurred in a conserved region involved in receptor interactions among morbilliviruses, implying that this region is a target for cross-reactive neutralizing antibodies. Copyright © 2015 Elsevier Inc. All rights reserved.

High temperature dissolution of chromium substituted nickel ferrite in nitrilotriacetic acid medium

Energy Technology Data Exchange (ETDEWEB)

Sathyaseelan, V.S.; Chandramohan, P.; Velmurugan, S., E-mail: svelu@igcar.gov.in

2016-12-01

High temperature (HT) dissolution of chromium substituted nickel ferrite was carried out with relevance to the decontamination of nuclear reactors by way of chemical dissolution of contaminated corrosion product oxides present on stainless steel coolant circuit surfaces. Chromium substituted nickel ferrites of composition, NiFe{sub (2−x)}Cr{sub x}O{sub 4} (x ≤ 1), was synthetically prepared and characterized. HT dissolution of these oxides was carried out in nitrilotriacetic acid medium at 160 °C. Dissolution was remarkably increased at 160 °C when compared to at 85 °C in a reducing decontamination formulation. Complete dissolution could be achieved for the oxides with chromium content 0 and 0.2. Increasing the chromium content brought about a marked reduction in the dissolution rate. About 40 fold decrease in rate of dissolution was observed when chromium was increased from 0 to 1. The rate of dissolution was not very significantly reduced in the presence of N{sub 2}H{sub 4}. Dissolution of oxide was found to be stoichiometric. - Highlights: • Dissolution of NiFe{sub (2−x)}Cr{sub x}O{sub 4} was remarkably increased at 160 °C in NTA medium. • The dissolution was significantly decreasing with the increase in Cr content in the oxide. • Dissolution rate is dependent on the lability of metal-oxo bonds. • The rate of dissolution was not significantly reduced in the presence of N{sub 2}H{sub 4.} • NTA at high temperature is effective for decontamination of stainless steel surfaces.

Allelochemicals in rye (Secale cereale L.): cultivar and tissue differences in the production of benzoxazinoids and phenolic acids.

Science.gov (United States)

Carlsen, Sandra C K; Kudsk, Per; Laursen, Bente; Mathiassen, Solvejg K; Mortensen, Anne G; Fomsgaard, Inge S

2009-02-01

In the present study, a range of benzoxazinoid compounds and phenolic acids, all known to be allelochemicals of rye, were identified and quantified in 13 rye cultivars grown at three different localities. Plant samples were collected in the spring at the time when an autumn-sown rye cover crop would be incorporated into the soil. Significant variations in content among shoots and roots were seen for all of the secondary metabolites, with non-methoxy-substituted benzoxazinoids (BX) dominating the shoots, whereas comparable levels were found in the concentrations of BX and methoxy-substituted benzoxazinoids (MBX) in the roots. This distribution of compounds may indicate different biosynthetic pathways and/or different mechanisms of action of these compounds. Concentrations not only depended on plant part, but also on the geographical location--with differences in contents of up to a factor of 5. These differences can probably be attributed to differences in growing conditions. The variation among cultivars was similar to that among geographical localities, with differences within localities of up to a factor of 7 in the shoots and a factor of 14 in the roots. In roots, the contents of the four phenolic acids and the benzoxazinoid 6-methoxybenzoxazolin-2-one (MBOA) were correlated. In shoots, the contents of the two benzoic acids were correlated with each other, whereas the two cinnamic acids were correlated with MBOA and several other benzoxazinoids. The lack of correlation between MBOA and all other benzoxazinoids in the roots of rye might indicate that a hitherto unknown synthetic pathway exists for MBOA. The genes responsible for the synthesis of some of the benzoxazinoids have never been identified, and further gene expression studies are required to assess the observed correlation between the concentration of these compounds and other benzoxazinoids for which the responsible genes are known. The present study revealed a potential for breeding rye cultivars with

Crystal structure of olivetolic acid: a natural product from Cetrelia sanguinea (Schaer.).

Science.gov (United States)

Ismed, Friardi; Farhan, Aulia; Bakhtiar, Amri; Zaini, Erizal; Nugraha, Yuda Prasetya; Dwichandra Putra, Okky; Uekusa, Hidehiro

2016-11-01

The title compound, C 12 H 16 O 4 (systematic name: 2,4-dihy-droxy-6-pentyl-benzoic acid) is a natural product isolated from C. sanguinea (Schaer.) and is reported to have various pharmacological activities. The mol-ecule is approximately planar (r.m.s. deviation for the non-H atoms = 0.096 Å) and features an intra-molecular O-H⋯O hydrogen bond. In the crystal, each olivetolic acid mol-ecule is connected to three neighbours via O-H⋯O hydrogen bonds, generating (10-1) sheets. This crystal is essentially isostructural with a related resorcinolic acid with a longer alkyl chain.

Substituted Pyrazinecarboxamides: Synthesis and Biological Evaluation

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Katarina Kralova

2006-03-01

Full Text Available Condensation of the corresponding chlorides of some substituted pyrazine-2-carboxylic acids (pyrazine-2-carboxylic acid, 6-chloropyrazine-2-carboxylic acid, 5-tert-butylpyrazine-2-carboxylic acid or 5-tert-butyl-6-chloropyrazine-2-carboxylic acid withvarious ring-substituted aminothiazoles or anilines yielded a series of amides. Thesyntheses, analytical and spectroscopic data of thirty newly prepared compounds arepresented. Structure-activity relationships between the chemical structures and the anti-mycobacterial, antifungal and photosynthesis-inhibiting activity of the evaluatedcompounds are discussed. 3,5-Bromo-4-hydroxyphenyl derivatives of substitutedpyrazinecarboxylic acid, 16-18, have shown the highest activity against Mycobacteriumtuberculosis H37Rv (54-72% inhibition. The highest antifungal effect againstTrichophyton mentagrophytes, the most susceptible fungal strain tested, was found for5-tert-butyl-6-chloro-N-(4-methyl-1,3-thiazol-2-ylpyrazine-2-carboxamide (8, MIC =31.25 μmol·mL-1. The most active inhibitors of oxygen evolution rate in spinachMolecules 2006, 11 243 chloroplasts were the compounds 5-tert-butyl-6-chloro-N-(5-bromo-2-hydroxyphenyl- pyrazine-2-carboxamide (27, IC50 = 41.9 μmol·L-1 and 5-tert-butyl-6-chloro-N-(1,3- thiazol-2-yl-pyrazine-2-carboxamide (4, IC50 = 49.5 μmol·L-1.

Characterization and quantification of flavonoids and organic acids over fruit development in American cranberry (Vaccinium macrocarpon) cultivars using HPLC and APCI-MS/MS.

Science.gov (United States)

Wang, Yifei; Johnson-Cicalese, Jennifer; Singh, Ajay P; Vorsa, Nicholi

2017-09-01

Cranberry flavonoids, including anthocyanins, flavonol glycosides and proanthocyanidins, and organic acids were characterized and quantified by HPLC and LC-MS/MS during fruit development and ripening in eight cranberry cultivars. Anthocyanin biosynthesis initiated at early fruit development and reached highest level in mature fruit, with significant differences between cultivars. Major flavonol glycosides, including the most abundant quercetin-3-galactoside and myricetin-3-galactoside, showed consistent concentrations during the season with moderate fluctuation, and were at similar levels in mature fruits of the eight cultivars. Proanthocyanidins declined during fruit development and then increased slightly in later maturation stages. Levels of various proanthocyanidin oligomers/polymers with different degree-of-polymerization were highly correlated within a cultivar during fruit development. Cultivars with coancestry exhibited similar levels (high/low) of anthocyanins or proanthocyanidins, indicating genetic effects on biosynthesis of such flavonoids. All cultivars showed similar levels of malic and citric acids, and declining levels of quinic acid during fruit development. Benzoic acid was extremely low early in the season and increased sharply during fruit ripening. Levels of quinic and citric acids were significantly different among cultivars in the mature fruit. Concentrations of proanthocyanidins, anthocyanins, quinic acid and benzoic acid have a strong developmental association in developing ovaries. Copyright © 2017 Elsevier B.V. All rights reserved.

Partition of selected food preservatives in fish oil-water systems

DEFF Research Database (Denmark)

Cheng, Hongyuan; Friis, Alan; Leth, Torben

2010-01-01

The partition coefficients (Kow) of benzoic acid and sorbic acid in systems of fish oil (sand eel)–water, fish oil–buffer solution, rape oil–water and olive oil–water were experimentally determined in a temperature range from 5 to 43 °C and pH from 4.5 to 6.5 °C. The dimerization of benzoic acid...... in fish oil–water system was observed at 25 °C. Two modifications have been made to the Nordic Food Analysis Standard for the determination of sorbic acid by HPLC. The experimental results show that the Kow of benzoic acid and sorbic acid in fish oil–buffer system is ca. 100 times lower than that in fish...... oil–water system. The Kow values of benzoic acid and sorbic acid in fish oil and water system decrease with increasing system pH values. The partition coefficients of plant origin and fish origin oils are in the same order of magnitude even though their molecular structures are very different....

Steric structure and thermodynamic aspects of Dy3+ complexes with aminobenzoic acids in aqueous solutions

International Nuclear Information System (INIS)

Kondrashina, Yu.G.; Mustafina, A.R.; Vul'fson, S.G.

1994-01-01

Stability and structure of dysprosium(3) aminobenzoate complexes with molar ratios Dy:L 1:1 and 1:2 (HL-aminobenzoic acid) in aqueous solutions are determined on the basis of pH-metric and paramagnetic birefringence data. The increase of conjugation effect in the series of benzoic, meta- ortho-, and para-aminobenzoic acid results in the increase of stability of 1:1 and 1:2 complexes. Features of the structure and coordination of ligands in dysprosium complexes with meta-, ortho-, and para-aminobenzoic acid are considered. 11 refs.; 4 figs.; 2 tabs

New gene cluster from the thermophile Bacillus fordii MH602 in the conversion of DL-5-substituted hydantoins to L-amino acids.

Science.gov (United States)

Mei, Yan-Zhen; Wan, Yong-Min; He, Bing-Fang; Ying, Han-Jie; Ouyang, Ping-Kai

2009-12-01

The thermophile Bacillus fordii MH602 was screened for stereospecifically hydrolyzing DL-5-substituted hydantoins to L-alpha-amino acids. Since the reaction at higher temperature, the advantageous for enhancement of substrate solubility and for racemization of DL-5-substituted hydantoins during the conversion were achieved. The hydantoin metabolism gene cluster from thermophile was firstly reported in this paper. The genes involved in hydantoin utilization (hyu) were isolated on an 8.2 kb DNA fragment by Restriction Site-dependent PCR, and six ORFs were identified by DNA sequence analysis. The hyu gene cluster contained four genes with novel cluster organization characteristics: the hydantoinase gene hyuH, putative transport protein hyuP, hyperprotein hyuHP, and L-carbamoylase gene hyuC. The hyuH and hyuC genes were heterogeneously expressed in E. coli. The results indicated that hyuH and hyuC are involved in the conversion of DL-5-substituted hydantoins to an N-carbamyl intermediate that is subsequently converted to L-alpha-amino acids. Hydantoinase and carbamoylase from B. fordii MH602 comparing respectively with reported hydantoinase and carbamoylase showed the highest identities of 71% and 39%. The novel cluster organization characteristics and the difference of the key enzymes between thermopile B. fordii MH602 and other mesophiles were presumed to be related to the evolutionary origins of concerned metabolism.

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

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Mohamed Touaibia

2012-12-01

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

Sedimentary records of hydroxylated and methoxylated polybrominated diphenyl ethers in the southern Yellow Sea.

Science.gov (United States)

Fan, Ying; Lan, Jing; Zhao, Zongshan; Zhao, Meixun

2014-07-15

Although hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have caused much concern in recent years, few reports had discussed on their input history. In this study, we measured the contents of nine MeO-BDEs, ten OH-BDEs, and total organic carbon (TOC) of two sediment cores from the southern Yellow Sea. 6-MeO-BDE-47, 2'-MeO-BDE-68, 6-OH-BDE-47, and 2'-OH-BDE-68 were the predominant congeners in HH12, while only 2'-OH-BDE-68 and 6-OH-BDE-47 were frequently detected in core HH11. The records showed that OH-/MeO-BDEs in both cores had increased rapidly since the 1950s. Their existence was detected at the bottom layers (∼1800 s) prior to the production of PBDEs (1960s), thus OH-/MeO-BDEs originate from natural origins rather than artificial PBDEs. Comparisons between TOC and OH-/MeO-BDEs indicated that TOC is a potential factor affecting the accumulation of OH-/MeO-BDEs in marine environments. Similar trends and significant correlations between OH-BDEs and MeO-BDEs suggest their common origins or interconversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluating the efficacy of a structure-derived amino acid substitution matrix in detecting protein homologs by BLAST and PSI-BLAST

OpenAIRE

Goonesekere, Nalin CW

2009-01-01

Nalin CW GoonesekereDepartment of Chemistry and Biochemistry, University of Northern iowa, Cedar Falls, IA, USAAbstract: The large numbers of protein sequences generated by whole genome sequencing projects require rapid and accurate methods of annotation. The detection of homology through computational sequence analysis is a powerful tool in determining the complex evolutionary and functional relationships that exist between proteins. Homology search algorithms employ amino acid substitution ...

Greener Friedel-Crafts Acylation using Microwave-enhanced reactivity of Bismuth Triflate in the Friedel-Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

DEFF Research Database (Denmark)

Tran, Phuong Hoang; Nguyen, Hai Truong; Hansen, Poul Erik

2017-01-01

An efficient and facile bismuth trifluoromethanesulfonate-catalyzed benzoylation of aromatic compounds using benzoic anhydride under solvent-free microwave irradiation has been developed. The microwave-assisted Friedel-Crafts benzoylation results in good yields within short reaction times. Bismuth...

40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

Science.gov (United States)

2010-07-01

... naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721.981 Protection of Environment...-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new... naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is subject to...

Effect of chemical substitutions on photo-switching properties of 3-hydroxy-picolinic acid studied by ab initio methods

International Nuclear Information System (INIS)

Rode, Michał F.; Sobolewski, Andrzej L.

2014-01-01

Effect of chemical substitutions to the molecular structure of 3-hydroxy-picolinic acid on photo-switching properties of the system operating on excited-state intramolecular double proton transfer (d-ESIPT) process [M. F. Rode and A. L. Sobolewski, Chem. Phys. 409, 41 (2012)] was studied with the aid of electronic structure theory methods. It was shown that simultaneous application of electron-donating and electron-withdrawing substitutions at certain positions of the molecular frame increases the height of the S 0 -state tautomerization barrier (ensuring thermal stability of isomers) and facilitates a barrierless access to the S 1 /S 0 conical intersection from the Franck-Condon region of the S 1 potential-energy surface. Results of study point to the conclusion that the most challenging issue for practical design of a fast molecular photoswitch based on d-ESIPT phenomenon are to ensure a selectivity of optical excitation of a given tautomeric form of the system

Effect of chemical substitutions on photo-switching properties of 3-hydroxy-picolinic acid studied by ab initio methods

Science.gov (United States)

Rode, Michał F.; Sobolewski, Andrzej L.

2014-02-01

Effect of chemical substitutions to the molecular structure of 3-hydroxy-picolinic acid on photo-switching properties of the system operating on excited-state intramolecular double proton transfer (d-ESIPT) process [M. F. Rode and A. L. Sobolewski, Chem. Phys. 409, 41 (2012)] was studied with the aid of electronic structure theory methods. It was shown that simultaneous application of electron-donating and electron-withdrawing substitutions at certain positions of the molecular frame increases the height of the S0-state tautomerization barrier (ensuring thermal stability of isomers) and facilitates a barrierless access to the S1/S0 conical intersection from the Franck-Condon region of the S1 potential-energy surface. Results of study point to the conclusion that the most challenging issue for practical design of a fast molecular photoswitch based on d-ESIPT phenomenon are to ensure a selectivity of optical excitation of a given tautomeric form of the system.

Large differences in proportions of harmful and benign amino acid substitutions between proteins and diseases.

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Schaafsma, Gerard C P; Vihinen, Mauno

2017-07-01

Genes and proteins are known to have differences in their sensitivity to alterations. Despite numerous sequencing studies, proportions of harmful and harmless substitutions are not known for proteins and groups of proteins. To address this question, we predicted the outcome for all possible single amino acid substitutions (AASs) in nine representative protein groups by using the PON-P2 method. The effects on 996 proteins were studied and vast differences were noticed. Proteins in the cancer group harbor the largest proportion of harmful variants (42.1%), whereas the non-disease group of proteins not known to have a disease association and not involved in the housekeeping functions had the lowest number of harmful variants (4.2%). Differences in the proportions of the harmful and benign variants are wide within each group, but they still show clear differences between the groups. Frequently appearing protein domains show a wide spectrum of variant frequencies, whereas no major protein structural class-specific differences were noticed. AAS types in the original and variant residues showed distinctive patterns, which are shared by all the protein groups. The observations are relevant for understanding genetic bases of diseases, variation interpretation, and for the development of methods for that purpose. © 2017 Wiley Periodicals, Inc.

An amino acid substitution (L925V associated with resistance to pyrethroids in Varroa destructor.

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Joel González-Cabrera

Full Text Available The Varroa mite, Varroa destructor, is an important pest of honeybees and has played a prominent role in the decline in bee colony numbers over recent years. Although pyrethroids such as tau-fluvalinate and flumethrin can be highly effective in removing the mites from hives, their intensive use has led to many reports of resistance. To investigate the mechanism of resistance in UK Varroa samples, the transmembrane domain regions of the V. destructor voltage-gated sodium channel (the main target site for pyrethroids were PCR amplified and sequenced from pyrethroid treated/untreated mites collected at several locations in Central/Southern England. A novel amino acid substitution, L925V, was identified that maps to a known hot spot for resistance within the domain IIS5 helix of the channel protein; a region that has also been proposed to form part of the pyrethroid binding site. Using a high throughput diagnostic assay capable of detecting the mutation in individual mites, the L925V substitution was found to correlate well with resistance, being present in all mites that had survived tau-fluvalinate treatment but in only 8 % of control, untreated samples. The potential for using this assay to detect and manage resistance in Varroa-infected hives is discussed.

Phenolic Acids from Wheat Show Different Absorption Profiles in Plasma: A Model Experiment with Catheterized Pigs

DEFF Research Database (Denmark)

Nørskov, Natalja; Hedemann, Mette Skou; Theil, Peter Kappel

2013-01-01

The concentration and absorption of the nine phenolic acids of wheat were measured in a model experiment with catheterized pigs fed whole grain wheat and wheat aleurone diets. Six pigs in a repeated crossover design were fitted with catheters in the portal vein and mesenteric artery to study...... the absorption of phenolic acids. The difference between the artery and the vein for all phenolic acids was small, indicating that the release of phenolic acids in the large intestine was not sufficient to create a porto-arterial concentration difference. Although, the porto-arterial difference was small...... consumed. Benzoic acid derivatives showed low concentration in the plasma (phenolic acids, likely because it is an intermediate in the phenolic acid metabolism...

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

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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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Arsenic scavenging by aluminum-substituted ferrihydrites in a circumneutral pH river impacted by acid mine drainage.

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Adra, Areej; Morin, Guillaume; Ona-Nguema, Georges; Menguy, Nicolas; Maillot, Fabien; Casiot, Corinne; Bruneel, Odile; Lebrun, Sophie; Juillot, Farid; Brest, Jessica

2013-11-19

Ferrihydrite (Fh) is a nanocrystalline ferric oxyhydroxide involved in the retention of pollutants in natural systems and in water-treatment processes. The status and properties of major chemical impurities in natural Fh is however still scarcely documented. Here we investigated the structure of aluminum-rich Fh, and their role in arsenic scavenging in river-bed sediments from a circumneutral river (pH 6-7) impacted by an arsenic-rich acid mine drainage (AMD). Extended X-ray absorption fine structure (EXAFS) spectroscopy at the Fe K-edge shows that Fh is the predominant mineral phase forming after neutralization of the AMD, in association with minor amount of schwertmannite transported from the AMD. TEM-EDXS elemental mapping and SEM-EDXS analyses combined with EXAFS analysis indicates that Al(3+) substitutes for Fe(3+) ions into the Fh structure in the natural sediment samples, with local aluminum concentration within the 25-30 ± 10 mol %Al range. Synthetic aluminous Fh prepared in the present study are found to be less Al-substituted (14-20 ± 5 mol %Al). Finally, EXAFS analysis at the arsenic K-edge indicates that As(V) form similar inner-sphere surface complexes on the natural and synthetic Al-substituted Fh studied. Our results provide direct evidence for the scavenging of arsenic by natural Al-Fh, which emphasize the possible implication of such material for scavenging pollutants in natural or engineered systems.

Characterization of polygalacturonases from fruit spoilage Fusarium ...

African Journals Online (AJOL)

The most chemical compounds caused moderate inhibitory effect except benzoic and citric acids which had strong inhibitory effect on the polygalacturonases. The benzoic and citric acids were used as antifungal compounds for F. oxysporum and A. tubingensis. The citric acid was found to be more effective against fungal ...

A novel ionic liquid-modified organic-polymer monolith as the sorbent for in-tube solid-phase microextraction of acidic food additives.

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Wang, Ting-Ting; Chen, Yi-Hui; Ma, Jun-Feng; Hu, Min-Jie; Li, Ying; Fang, Jiang-Hua; Gao, Hao-Qi

2014-08-01

A novel ionic liquid-modified organic-polymer monolithic capillary column was prepared and used for in-tube solid-phase microextraction (SPME) of acidic food additives. The primary amino group of 1-aminopropyl-3-methylimidazolium chloride was reacted with the epoxide group of glycidyl methacrylate. The as-prepared new monomer was then copolymerized in situ with acrylamide and N,N'-methylenebisacrylamide in the presence of polyethylene glycol (PEG)-8000 and PEG-10,000 as porogens. The extraction performance of the developed monolithic sorbent was evaluated for benzoic acid, 3-hydroxybenzoic acid, cinnamic acid, 2,4-dichlorophenoxyacetic acid, and 3-(trifluoromethyl)-cinnamic acid. Such a sorbent, bearing hydrophobic and anion-exchange groups, had high extraction efficiency towards the test compounds. The adsorption capacities for the analytes dissolved in water ranged from 0.18 to 1.74 μg cm(-1). Good linear calibration curves (R(2) > 0.99) were obtained, and the limits of detection (S/N = 3) for the analytes were found to be in the range 1.2-13.5 ng mL(-1). The recoveries of five acidic food additives spiked in Coca-Cola beverage samples ranged from 85.4 % to 98.3 %, with RSD less than 6.9 %. The excellent applicability of the ionic liquid (IL)-modified monolithic column was further tested by the determination of benzoic acid content in Sprite samples, further illustrating its good potential for analyzing food additives in complex samples.

Facile syntheses of isotope-labeled chiral octahydroindole-2-carboxylic acid and its N-methyl analog

International Nuclear Information System (INIS)

Yinsheng Zhang

2012-01-01

We have synthesized deuterium and carbon-14 labeled enantiomerically pure octahydroindole-2-carboxylic acid (PD0140417), N-methyl octahydroindole-2-carboxylic acid (PD0348183) and their racemic analogs (PD0108405 and PD0338055). [ring-U- 14 C]PD0140417 was prepared from [ring-U- 14 C]benzoic acid in a seven-step synthesis in 6.2% overall radiochemical yield. [ 14 C]PD0348183 was prepared from [ 14 C]BaCO 3 in a five-step synthesis in 16% radiochemical yield. Additionally, [D]PD0108405 and [D]PD0338055 were synthesized by direct platinum-catalyzed hydrogenation with deuterium gas. (author)

Association of Dietary Proportions of Macronutrients with Visceral Adiposity Index: Non-Substitution and Iso-Energetic Substitution Models in a Prospective Study.

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Moslehi, Nazanin; Ehsani, Behnaz; Mirmiran, Parvin; Hojjat, Parvane; Azizi, Fereidoun

2015-10-26

We aimed to investigate associations between dietary macronutrient proportions and prospective visceral adiposity index changes (ΔVAI). The study included 1254 adults (18-74 years), from the Tehran Lipid and Glucose Study (TLGS), who were followed for three years. Dietary intakes were assessed twice using food frequency questionnaires. Associations of dietary macronutrient with ΔVAI and risk of visceral adiposity dysfunction (VAD) after three years were investigated. The percentage of energy intake from protein in the total population, and from fat in women, were associated with higher increases in VAI. A 5% higher energy intake from protein substituted for carbohydrate, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) was associated with higher ΔVAI. Higher energy intake from animal protein substituted for PUFAs was positively associated with ΔVAI. Substituting protein and PUFAs with MUFAs were related to higher ΔVAI. The associations were similar in men and women, but reached significance mostly among women. Risk of VAD was increased when 1% of energy from protein was replaced with MUFAs. Substituting protein for carbohydrate and fat, and fat for carbohydrate, resulted in increased risk of VAD in women. Higher dietary proportions of protein and animal-derived MUFA may be positively associated with ΔVAI and risk of VAD.

Effects of a naturally occurring amino acid substitution in bovine PrP: a model for inherited prion disease in a natural host species

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The most common hereditary prion disease is human Creutzfeldt-Jakob disease (CJD) associated with a mutation in the prion gene (PRNP) resulting in a glutamic acid to lysine substitution at position 200 (E200K) in the prion protein. Models of E200K CJD in transgenic mice have proven interesting but h...

Amino acid substitutions of Na,K-ATPase conferring decreased sensitivity to cardenolides in insects compared to mammals.

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Dalla, Safaa; Swarts, Herman G P; Koenderink, Jan B; Dobler, Susanne

2013-12-01

Mutagenesis analyses and a recent crystal structure of the mammalian Na,K-ATPase have identified amino acids which are responsible for high affinity binding of cardenolides (such as ouabain) which at higher doses block the enzyme in the phosphorylated state. Genetic analysis of the Na,K-ATPase of insects adapted to cardenolides in their food plants revealed that some species possess substitutions which confer strongly increased resistance to ouabain in the mammalian enzyme such as the substitution T797A or combined substitutions at positions 111 and 122. To test for the effect of these mutations against the background of insect Na,K-ATPase, we here expressed the ouabain sensitive Na,K-ATPase α-subunit of Drosophila melanogaster together with the β-subunit Nrv3 in baculovirus-infected Sf9 cells and introduced the substitutions N122H, T797A, Q111T-N122H, Q111V-N122H, all of which have been observed in cardenolide-adapted insects. While all constructs showed similar expression levels, ouabain affinity of mutated Na,K-ATPases was reduced compared to the wild-type fly enzyme. Ouabain sensitivity of the ATPase activity in inhibition assays was significantly decreased by all mutations, yet whereas the IC₅₀ for the single mutations of N122H (61.0 μM) or T797A (63.3 μM) was increased roughly 250-fold relative to the wild-type (0.24 μM), the double mutations of Q111V-N122H (IC₅₀ 550 μM) and Q111T-N122H (IC₅₀ 583 μM) proved to be still more effective yielding a 2.250-fold increased resistance to ouabain. The double mutations identified in cardenolide-adapted insects are more effective in reducing ouabain sensitivity of the enzyme than those found naturally in the rat Na,K-ATPase (Q111R-N122D) or in mutagenesis screens of the mammalian enzyme. Obviously, the intense selection pressure on cardenolide exposed insects has resulted in very efficient substitutions that decrease cardenolide sensitivity extremely. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of yttrium substitution on the magnetic properties of magnetite nanoparticles

International Nuclear Information System (INIS)

Mozaffari, M.; Amighian, J.; Tavakoli, R.

2015-01-01

Superparamagnetic Y-substituted magnetite (Y x Fe 3–x O 4 ,with x=0.00, 0.10, 0.15, 0.20 and 0.40) nanoparticles were synthesized via hydrothermal reduction route in the presence of citric acid. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM) and gradient field thermomagnetic measurement. The results showed that a minimum amount of citric acid is required to obtain single phase Y-substituted magnetite nanoparticles. Citric acid acts as a modulator and reducing agent in the formation of spinel structure and controls nanoparticle size and crystallinity. Mean crystallite sizes of the single-phase powders were estimated by Williamson–Hall method. Curie temperature measurement of the samples shows that as yttrium content increases, the Curie temperature decreases. Magnetic measurements show that the saturation magnetization of the samples decreases as x increases up to 0.15 and then increases to x=0.20 and finally decreases again for x=0.40. - Highlights: • Single phase yttrium substituted magnetite nanoparticles were synthesized by hydrothermal-reduction route. • Citric acid plays a key role in reduction of Fe 3+ to Fe 2+ , which is necessary for the formation of magnetite phase. • It is possible to substitute yttrium ions for iron ones as high as x=0.4 by hydrothermal reduction route. • Pure magnetite nanoparticles prepared by this route has a high saturation magnetization. • Yttrium substituted magnetite nanoparticles are superparamagnet at room temperature

[Anti-arrhythmic action of some amidinohydrazone substituted benzophenones. 1. Synthesis of new amidinohydrazone and N-phenylamidinohydrazone substituted benzophenones].

Science.gov (United States)

Richter, P H; Kasbohm, K; Besch, A; Hagen, A

1992-10-01

The title compounds are synthesized as a rule by condensation of substituted benzophenones and derivatives of aminoguanidine in the presence of up to 2.5 moles of an anorganic acid. They can be obtained alternatively via corresponding hydrazones, thiosemicarbazones or methylthiothiocarbonylhydrazones.

A new p-hydroxybenzoic acid derivative from an endophytic fungus Penicillium sp. of Nerium indicum.

Science.gov (United States)

Ma, Yang-Min; Qiao, Ke; Kong, Yang; Guo, Lin-Xin; Li, Meng-Yun; Fan, Chao

2017-12-01

A new p-hydroxybenzoic acid derivative named 4-(2'R, 4'-dihydroxybutoxy) benzoic acid (1) was isolated from the fermentation of Penicillium sp. R22 in Nerium indicum. The structure was elucidated by means of spectroscopic (HR-ESI-MS, NMR, IR, UV) and X-ray crystallographic methods. The antibacterial and antifungal activity of compound 1 was tested, and the results showed that compound 1 revealed potent antifungal activity against Colletotrichum gloeosporioides, Alternaria alternata, and Alteranria brassicae with MIC value of 31.2 μg/ml.

Effect of specific amino acid substitutions in the putative fusion peptide of structural glycoprotein E2 on Classical Swine Fever Virus replication

International Nuclear Information System (INIS)

Fernández-Sainz, I.J.; Largo, E.; Gladue, D.P.; Fletcher, P.; O’Donnell, V.; Holinka, L.G.; Carey, L.B.; Lu, X.; Nieva, J.L.; Borca, M.V.

2014-01-01

E2, along with E rns and E1, is an envelope glycoprotein of Classical Swine Fever Virus (CSFV). E2 is involved in several virus functions: cell attachment, host range susceptibility and virulence in natural hosts. Here we evaluate the role of a specific E2 region, 818 CPIGWTGVIEC 828 , containing a putative fusion peptide (FP) sequence. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how individual amino acid substitutions within this region of E2 may affect replication of BICv. A synthetic peptide representing the complete E2 FP amino acid sequence adopted a β-type extended conformation in membrane mimetics, penetrated into model membranes, and perturbed lipid bilayer integrity in vitro. Similar peptides harboring amino acid substitutions adopted comparable conformations but exhibited different membrane activities. Therefore, a preliminary characterization of the putative FP 818 CPIGWTGVIEC 828 indicates a membrane fusion activity and a critical role in virus replication. - Highlights: • A putative fusion peptide (FP) region in CSFV E2 protein was shown to be critical for virus growth. • Synthetic FPs were shown to efficiently penetrate into lipid membranes using an in vitro model. • Individual residues in the FP affecting virus replication were identified by reverse genetics. • The same FP residues are also responsible for mediating membrane fusion

Effect of specific amino acid substitutions in the putative fusion peptide of structural glycoprotein E2 on Classical Swine Fever Virus replication

Energy Technology Data Exchange (ETDEWEB)

Fernández-Sainz, I.J. [Plum Island Animal Disease Center, ARS, USDA (United States); Largo, E. [Biophysics Unit (CSIC-UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao (Spain); Gladue, D.P.; Fletcher, P. [Plum Island Animal Disease Center, ARS, USDA (United States); O’Donnell, V. [Plum Island Animal Disease Center, ARS, USDA (United States); Plum Island Animal Disease Center, DHS, Greenport, NY 11944 (United States); Holinka, L.G. [Plum Island Animal Disease Center, ARS, USDA (United States); Carey, L.B. [Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), E-08003 Barcelona (Spain); Lu, X. [Plum Island Animal Disease Center, DHS, Greenport, NY 11944 (United States); Nieva, J.L. [Biophysics Unit (CSIC-UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao (Spain); Borca, M.V., E-mail: manuel.borca@ars.usda.gov [Plum Island Animal Disease Center, ARS, USDA (United States)

2014-05-15

E2, along with E{sup rns} and E1, is an envelope glycoprotein of Classical Swine Fever Virus (CSFV). E2 is involved in several virus functions: cell attachment, host range susceptibility and virulence in natural hosts. Here we evaluate the role of a specific E2 region, {sup 818}CPIGWTGVIEC{sup 828}, containing a putative fusion peptide (FP) sequence. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how individual amino acid substitutions within this region of E2 may affect replication of BICv. A synthetic peptide representing the complete E2 FP amino acid sequence adopted a β-type extended conformation in membrane mimetics, penetrated into model membranes, and perturbed lipid bilayer integrity in vitro. Similar peptides harboring amino acid substitutions adopted comparable conformations but exhibited different membrane activities. Therefore, a preliminary characterization of the putative FP {sup 818}CPIGWTGVIEC{sup 828} indicates a membrane fusion activity and a critical role in virus replication. - Highlights: • A putative fusion peptide (FP) region in CSFV E2 protein was shown to be critical for virus growth. • Synthetic FPs were shown to efficiently penetrate into lipid membranes using an in vitro model. • Individual residues in the FP affecting virus replication were identified by reverse genetics. • The same FP residues are also responsible for mediating membrane fusion.

Amino Acid Substitutions Improve the Immunogenicity of H7N7HA Protein and Protect Mice against Lethal H7N7 Viral Challenge.

Directory of Open Access Journals (Sweden)

Subaschandrabose Rajesh Kumar

Full Text Available Avian influenza A H7N7/NL/219/03 virus creates a serious pandemic threat to human health because it can transmit directly from domestic poultry to humans and from human to human. Our previous vaccine study reported that mice when immunized intranasally (i.n with live Bac-HA were protected from lethal H7N7/NL/219/03 challenge, whereas incomplete protection was obtained when administered subcutaneously (s.c due to the fact that H7N7 is a poor inducer of neutralizing antibodies. Interestingly, our recent vaccine studies reported that mice when vaccinated subcutaneously with Bac-HA (H7N9 was protected against both H7N9 (A/Sh2/2013 and H7N7 virus challenge. HA1 region of both H7N7 and H7N9 viruses are differ at 15 amino acid positions. Among those, we selected three amino acid positions (T143, T198 and I211 in HA1 region of H7N7. These amino acids are located within or near the receptor binding site. Following the selection, we substituted the amino acid at these three positions with amino acids found on H7N9HA wild-type. In this study, we evaluate the impact of amino acid substitutions in the H7N7 HA-protein on the immunogenicity. We generated six mutant constructs from wild-type influenza H7N7HA cDNA by site directed mutagenesis, and individually expressed mutant HA protein on the surface of baculovirus (Bac-HAm and compared their protective efficacy of the vaccines with Bac-H7N7HA wild-type (Bac-HA by lethal H7N7 viral challenge in a mouse model. We found that mice immunized subcutaneously with Bac-HAm constructs T143A or T198A-I211V or I211V-T143A serum showed significantly higher hemagglutination inhibition and neutralization titer against H7N7 and H7N9 viruses when compared to Bac-HA vaccinated mice groups. We also observed low level of lung viral titer, negligible weight loss and complete protection against lethal H7N7 viral challenge. Our results indicated that amino acid substitution at position 143 or 211 improve immunogenicity of H7N7HA

Active Sites of Reduced Epidermal Fluorescence1 (REF1) Isoforms Contain Amino Acid Substitutions That Are Different between Monocots and Dicots.

Science.gov (United States)

Missihoun, Tagnon D; Kotchoni, Simeon O; Bartels, Dorothea

2016-01-01

Plant aldehyde dehydrogenases (ALDHs) play important roles in cell wall biosynthesis, growth, development, and tolerance to biotic and abiotic stresses. The Reduced Epidermal Fluorescence1 is encoded by the subfamily 2C of ALDHs and was shown to oxidise coniferaldehyde and sinapaldehyde to ferulic acid and sinapic acid in the phenylpropanoid pathway, respectively. This knowledge has been gained from works in the dicotyledon model species Arabidopsis thaliana then used to functionally annotate ALDH2C isoforms in other species, based on the orthology principle. However, the extent to which the ALDH isoforms differ between monocotyledons and dicotyledons has rarely been accessed side-by-side. In this study, we used a phylogenetic approach to address this question. We have analysed the ALDH genes in Brachypodium distachyon, alongside those of other sequenced monocotyledon and dicotyledon species to examine traits supporting either a convergent or divergent evolution of the ALDH2C/REF1-type proteins. We found that B. distachyon, like other grasses, contains more ALDH2C/REF1 isoforms than A. thaliana and other dicotyledon species. Some amino acid residues in ALDH2C/REF1 isoforms were found as being conserved in dicotyledons but substituted by non-equivalent residues in monocotyledons. One example of those substitutions concerns a conserved phenylalanine and a conserved tyrosine in monocotyledons and dicotyledons, respectively. Protein structure modelling suggests that the presence of tyrosine would widen the substrate-binding pocket in the dicotyledons, and thereby influence substrate specificity. We discussed the importance of these findings as new hints to investigate why ferulic acid contents and cell wall digestibility differ between the dicotyledon and monocotyledon species.

Active Sites of Reduced Epidermal Fluorescence1 (REF1 Isoforms Contain Amino Acid Substitutions That Are Different between Monocots and Dicots.

Directory of Open Access Journals (Sweden)

Tagnon D Missihoun

Full Text Available Plant aldehyde dehydrogenases (ALDHs play important roles in cell wall biosynthesis, growth, development, and tolerance to biotic and abiotic stresses. The Reduced Epidermal Fluorescence1 is encoded by the subfamily 2C of ALDHs and was shown to oxidise coniferaldehyde and sinapaldehyde to ferulic acid and sinapic acid in the phenylpropanoid pathway, respectively. This knowledge has been gained from works in the dicotyledon model species Arabidopsis thaliana then used to functionally annotate ALDH2C isoforms in other species, based on the orthology principle. However, the extent to which the ALDH isoforms differ between monocotyledons and dicotyledons has rarely been accessed side-by-side. In this study, we used a phylogenetic approach to address this question. We have analysed the ALDH genes in Brachypodium distachyon, alongside those of other sequenced monocotyledon and dicotyledon species to examine traits supporting either a convergent or divergent evolution of the ALDH2C/REF1-type proteins. We found that B. distachyon, like other grasses, contains more ALDH2C/REF1 isoforms than A. thaliana and other dicotyledon species. Some amino acid residues in ALDH2C/REF1 isoforms were found as being conserved in dicotyledons but substituted by non-equivalent residues in monocotyledons. One example of those substitutions concerns a conserved phenylalanine and a conserved tyrosine in monocotyledons and dicotyledons, respectively. Protein structure modelling suggests that the presence of tyrosine would widen the substrate-binding pocket in the dicotyledons, and thereby influence substrate specificity. We discussed the importance of these findings as new hints to investigate why ferulic acid contents and cell wall digestibility differ between the dicotyledon and monocotyledon species.

A novel amino acid substitution in a voltage-gated sodium channel is associated with knockdown resistance to permethrin in Aedes aegypti.

Science.gov (United States)

Chang, Cheng; Shen, Wen-Kai; Wang, Tzu-Ting; Lin, Ying-Hsi; Hsu, Err-Lieh; Dai, Shu-Mei

2009-04-01

To identify pertinent mutations associated with knockdown resistance to permethrin, the entire coding sequence of the voltage-gated sodium channel gene Aa-para was sequenced and analyzed from a Per-R strain with 190-fold resistance to permethrin and two susceptible strains of Aedes aegypti. The longest transcript, a 6441bp open reading frame, encodes 2147 amino acid residues with an estimated molecular mass of 241kDa. A total of 33 exons were found in the Aa-para gene over 293kb of genomic DNA. Three previously unreported optional exons were identified. The first two exons, m and n, were located within the intracellular domain I/II, and the third, f', was found within the II/III linkers. The two mutually exclusive exons, d and l, were the only alternative exons in all the cDNA clones sequenced in this study. The most distinct finding was a novel amino acid substitution mutation, D1794Y, located within the extracellular linker between IVS5 and IVS6, which is concurrent with the known V1023G mutation in Aa-para of the Per-R strain. The high frequency and coexistence of the two mutations in the Per-R strain suggest that they might exert a synergistic effect to provide the knockdown resistance to permethrin. Furthermore, both cDNA and genomic DNA data from the same individual mosquitoes have demonstrated that RNA editing was not involved in amino acid substitutions of the Per-R strain.

Heterocycles [h]-Fused Onto 4-Oxoquinoline-3-Carboxylic Acid, Part VIII [1]. Convenient Synthesis and Antimicrobial Properties of Substituted Hexahydro[1,4]diazepino[2,3-h]quinoline-9-carboxylic acid and Its Tetrahydroquino[7,8-b]benzodiazepine Analog

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Yusuf M. Al-Hiari

2008-11-01

Full Text Available [1,4]Diazepino[2,3-h]quinolone carboxylic acid 3 and its benzo-homolog tetrahydroquino[7,8-b]benzodiazepine-3-carboxylic acid 5 were prepared via PPAcatalyzed thermal lactamization of the respective 8-amino-7-substituted-1,4-dihydroquinoline-3-carboxylic acid derivatives 8, 10. The latter compounds were obtained by reduction of their 8-nitro-7-substituted-1,4-dihydroquinoline-3-carboxylic acid precursors 7, 9 which, in turn, were prepared by reaction of 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-1,4-dihydroquinoline-3-carboxylic acid (6 with each of β-alanine and anthranilic acid. All intermediates and target compounds were characterized using elemental analysis, NMR, IR and MS spectral data. The prepared targets and the intermediates have shown interesting antibacterial activity mainly against Gram positive strains. In particular, compound 8 showed good activity against S. aureus (MIC = 0.39 μg/mL and B. subtilis (MIC = 0.78 μg/mL. Compounds 5a and 9 have also displayed good antifungal activity against C. albicans (MIC = 1.56 μg/mL and 0.78 μg/mL, respectively. None of the compounds tested showed any anticancer activity against solid breast cancer cell line MCF-7 cells or a human breast adenocarcinoma cell line.

Synthesis and Application of Acid Dyes Based on 3-(4-Aminophenyl-5-benzylidene-2-substituted phenyl-3, 5-dihydroimidazol-4-one

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Devang N. Wadia

2008-01-01

Full Text Available A series of eight novel heterocyclic based monoazo acid dyes were synthesized using various substituted imidazol-4-one as diazo component and coupled with various amino-napthol sulphonic acids. The resultant dyes were characterized using standard spectroscopic methods and then dyeing performance on wool fabric was assessed. Final results concluded that exhaustion (%E of the dyes on wool fibers increased with decreasing pH of application and that fixation (%F of the dyes on wool fibers increased with increasing pH of application and the highest total fixation efficiency was achieved at pH 5. Wash and light fastness properties of prepared dyes showed encouraging results.

Expression, purification, crystallization and preliminary X-ray analysis of a novel N-substituted branched-chain l-amino-acid dioxygenase from Burkholderia ambifaria AMMD

International Nuclear Information System (INIS)

Qin, Hui-Min; Miyakawa, Takuya; Nakamura, Akira; Xue, You-Lin; Kawashima, Takashi; Kasahara, Takuya; Hibi, Makoto; Ogawa, Jun; Tanokura, Masaru

2012-01-01

Diffraction data were collected to a limiting resolution of 2.4 Å from a crystal of selenomethionyl-labelled SadA, an l-amino-acid dioxygenase. Ferrous ion- and α-ketoglutarate-dependent dioxygenase from Burkholderia ambifaria AMMD (SadA) catalyzes the C3-hydroxylation of N-substituted branched-chain l-amino acids, especially N-succinyl-l-leucine, coupled to the conversion of α-ketoglutarate to succinate and CO 2 . SadA was expressed in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method at 293 K. Crystals of selenomethionine-substituted SadA were obtained using a reservoir solution containing PEG 3000 as the precipitant at pH 9.5 and diffracted X-rays to 2.4 Å resolution. The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 49.3, b = 70.9, c = 148.2 Å. The calculated Matthews coefficient (V M = 2.1 Å 3 Da −1 , 41% solvent content) suggested that the crystal contains two molecules per asymmetric unit

Reactivity of H atoms and hydrated electrons with chlorobenzoic acids

Energy Technology Data Exchange (ETDEWEB)

Zona, Robert [Department of Nutritional Sciences, Section Radiation Biology, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria); Solar, Sonja [Department of Nutritional Sciences, Section Radiation Biology, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria)], E-mail: sonja.solar@univie.ac.at; Getoff, Nikola [Department of Nutritional Sciences, Section Radiation Biology, University of Vienna, UZAII, Althanstrasse 14, A-1090 Vienna (Austria); Sehested, Knud; Holcman, Jerzy [Environmental Science and Technology Department, RISO National Laboratory, DK-4000, Roskilde (Denmark)

2008-02-15

H radicals react with chlorobenzoic acids and chlorobenzene (k(H{sup {center_dot}}+substrates)=(0.7-1.5)x10{sup 9} dm{sup 3} mol{sup -1} s{sup -1}) by addition to the benzene ring forming H adducts with characteristic absorption bands in the range of 310-360 nm. The rate constants for their second-order decay are 2k=(3.5-6)x10{sup 8} dm{sup 3} mol{sup -1} s{sup -1}. By reduction with e{sub aq}{sup -} fragmentation and chloride release was established for 2- and 4-chlorobenzoic acid, for 3-chlorobenzoic acid the addition of electrons to the carboxylate group was observed by pulse radiolysis. By gamma radiolysis could be proved that these radical anions undergo intramolecular electron transfer and quantitave dechlorination. The efficiency in degradation was 4-chlorobenzoic acid>3-chlorobenzoic acid>2-chlorobenzoic acid. Benzoic acid was found as final product for all substrates.

Synthesis, Characterization and Antimicrobial Activity of New Thiadiazole Derivatives

Energy Technology Data Exchange (ETDEWEB)

Mullick, Pooja; Khan, Suroor A.; Verma, Surajpal; Alam, Ozair [Hamdard University, New Delhi (India)

2010-08-15

A series of thiadiazole derivatives were synthesized with differently substituted benzoic acids which were cyclized to give differently substituted thiazolidin-4-one. Elemental analysis, IR, {sup 1}H NMR, {sup 13}C NMR and mass spectral data confirmed the structure of the newly synthesized compounds. The derivatives of these moieties were evaluated for antimicrobial activity. Most of the synthesized compounds showed good antimicrobial activity at 200 and 100 μg/mL. Compounds showed most significant antibacterial activity against gram negative test organism Escherichia coli and most significant antifungal activity against test organisms Aspergillus niger and Candida albicans. It was observed that compounds with OCH{sub 3} at 3, 4 position of phenyl ring [5(a-l)] were more potent against microbes as compared to compounds having unsubstituted phenyl ring [4(a-l)].

Identification of lactic acid bacteria from chili bo, a Malaysian food ingredient.

Science.gov (United States)

Leisner, J J; Pot, B; Christensen, H; Rusul, G; Olsen, J E; Wee, B W; Muhamad, K; Ghazali, H M

1999-02-01

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28 degreesC with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg-1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.

Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Five-, Six-, and Seven-Membered β-Substituted Cyclic Enones: Enantioselective Construction of All-Carbon Quaternary Stereocenters

KAUST Repository

Kikushima, Kotaro

2011-05-11

The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters via 1,4-addition of arylboronic acids to β-substituted cyclic enones is reported. Reaction of a wide range of arylboronic acids and cyclic enones using a catalyst prepared from Pd(OCOCF(3))(2) and a chiral pyridinooxazoline ligand yields enantioenriched products bearing benzylic stereocenters. Notably, this transformation is tolerant to air and moisture, providing a practical and operationally simple method of synthesizing enantioenriched all-carbon quaternary stereocenters.

Studies on Synthesis of Some Novel Heterocyclic Azlactone Derivatives and Imidazolinone Derivatives and their Antimicrobial Activity

Directory of Open Access Journals (Sweden)

Rakesh N. Mistry

2005-01-01

Full Text Available p - Methyl benzoic acid on reaction with phosphorus pentachloride gives p - methyl benzoyl chloride derivative which on condensation with glycine gives p - methyl benzoyl glycine derivative. Now, this p - methyl benzoyl glycine derivative on condensation with various substituted aldehydes gives corresponding substituted 4 - [aryl methylidine] - 2 - [p - methyl phenyl] - oxazole - 5 - one derivatives [1(a-j]. Further, these derivatives [1(a-j] on condensation with 4 , 4’ - diamino diphenyl sulphone gives corresponding substituted imidazolinone - dibenzsulphone derivatives [2(a-j], on condensation with 4 , 4’ - diamino diphenyl methane gives corresponding substituted imidazolinone - dibenzmethane derivatives [3(a-j], on condensation with 4,4’- diamino benzanilide gives corresponding substituted imidazolinone - benzanilide derivatives [4(a-j] and on condensation with 2 - amino pyridine gives corresponding substituted imidazolinone - pyridine derivatives [5(a-j] respectively. Structure elucidation of synthesised compounds has been made on the basis of elemental analysis, I.R. spectral studies and 1H N.M.R. spectral studies. The antimicrobial activity of the synthesised compounds has been studied against the cultures “Staphylococcus aureus”, “Escherichia coli” and “Candela albicans”.

Structural investigation of liquid formic acid by neutron diffraction. II: Isotopic substitution for DCOO[H/D

International Nuclear Information System (INIS)

Bako, Imre; Schubert, Gabor; Megyes, Tuende; Palinkas, Gabor; Swan, Geoffrey I.; Dore, John; Bellisent-Funel, Marie-Claire

2004-01-01

New measurements of neutron diffraction data for four samples involving H/D isotopic substitution on the hydroxyl hydrogen of liquid formic acid at 20 deg C are reported. The results are combined with earlier measurements on [H/D]COOD to provide a full range of data. The determination of molecular conformation and bond-lengths has been made with a partial form-factor formalism and also using the 'Monte Carlo determination of g(r)' technique. The partial real-space correlation functions, RR, RH and HH are evaluated in each case and compared with existing computer simulations. The results confirm the strongly hydrogen-bonded nature of the liquid, but show that current molecular dynamics predictions based on transferable potentials do not give a very good representation of the structure. The observations provide a basis for a more detailed investigation and work is currently in progress. Ab initio quantum chemical calculations showed that the non-planar configuration suggested by Bertagnolli et al. [Ber. Bunsen. Phys. Chem. 88 (1984) 977; Ber. Bunsen. Phys. Chem. 89 (1985) 500], is very unlikely both for formic acid dimers and monomers

preparation and nucleophilic substitution of the 2,4,6

African Journals Online (AJOL)

Mgina

Three methods for preparation of D-amino acids by nucleophilic substitution on derivatives of ... bioactivity of the peptide (Wenger 1985, ... Acetic acid (0.29 mL, 5 mmol) was added, and the mixture was further stirred for 5 h at rt under ... methanol/dichloromethane) to yield a white ... temperature, diluted with water, extracted.

Crystal growth, vibrational, optical, thermal and theoretical studies of a nonlinear optical material: 2-Methyl 3,5-dinitrobenzoic acid

Energy Technology Data Exchange (ETDEWEB)

Sangeetha, K. [Department of Physics, Sri Sarada College for Women, Salem-16 (India); Guru Prasad, L. [Department of Science & Humanities, M. Kumarasamy College of Engineering, Karur (India); Mathammal, R. [Department of Physics, Sri Sarada College for Women, Salem-16 (India)

2016-11-15

Single crystals of 2-methyl 3,5-dinitro benzoic acid with reasonable size have been grown by slow evaporation solution growth method using ethanol as solvent. Quantum chemical calculation of 2-methyl 3,5-Dinitro benzoic acid was carried out by using DFT/B3LYP/6-31+G(d,p) method. The powder X-ray diffraction pattern was recorded and indexed. Both the experimental and theoretical vibrational spectrum validates the presence of functional groups. Polarizability, first order hyperpolarizability and the electric dipole moment values have been computed theoretically. The {sup 1}H and {sup 13}C NMR chemical shift of the molecule was calculated and compared with experimental results. TG/DSC analysis has been employed to understand the thermal and physio-chemical stability of the title compound. Frequency conversion property of the crystal was tested by Kurtz and Perry method. Optical absorption behavior of the grown crystal was examined by recording the optical spectrum and band gap energy was also estimated. The calculated HOMO and LUMO energy shows the charge transfer nature of the molecule.

Crystal structures of three anhydrous salts of the Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU with the ring-substituted benzoic acid analogues 4-aminobenzoic acid, 3,5-dinitrobenzoic acid and 3,5-dinitrosalicylic acid

Directory of Open Access Journals (Sweden)

Graham Smith

2016-03-01

Full Text Available The anhydrous salts of the Lewis base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU with 4-aminobenzoic acid [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 4-aminobenzoate, C9H17N2+·C7H6NO2− (I], 3,5-dinitrobenzoic acid [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 3,5-dinitrobenzoate, C9H17N2+·C7H3N2O6−, (II] and 3,5-dinitrosalicylic acid (DNSA [1-aza-8-azoniabicyclo[5.4.0]undec-7-ene 2-hydroxy-3,5-dinitrobenzoate, C9H17N2+·C7H3N2O7−, (III] have been determined and their hydrogen-bonded structures are described. In both (II and (III, the DBU cations have a common disorder in three of the C atoms of the six-membered ring moieties [site-occupancy factors (SOF = 0.735 (3/0.265 (3 and 0.686 (4/0.314 (4, respectively], while in (III, there is additional rotational disorder in the DNSA anion, giving two sites (SOF = 0.72/0.28, values fixed for the phenol group. In the crystals of (I and (III, the cation–anion pairs are linked through a primary N—H...Ocarboxyl hydrogen bond [2.665 (2 and 2.869 (3 Å, respectively]. In (II, the ion pairs are linked through an asymmetric three-centre R12(4, N—H...O,O′ chelate association. In (I, structure extension is through amine N—H...Ocarboxyl hydrogen bonds between the PABA anions, giving a three-dimensional structure. The crystal structures of (II and (III are very similar, the cation–anion pairs being associated only through weak C—H...O hydrogen bonds, giving in both overall two-dimensional layered structures lying parallel to (001. No π–π ring associations are present in any of the structures.

Interaction of theobromine with sodium benzoate

Energy Technology Data Exchange (ETDEWEB)

Nishijo, J.; Yonetani, I.

1982-03-01

The interaction of theobromine with sodium benzoate was investigated by PMR spectroscopy. The interaction of theobromine with pentadeuterated benzoic acid (benzoic acid-d5) was examined in the same manner but to a lesser degree. Chemical shifts of theobromine protons were determined as a function of sodium benzoate concentration in deuterium oxide at 30 and 15 degrees. Signals of both methyl groups of theobromine underwent significant upfield shifts when sodium benzoate was added to a theobromine solution. This fact suggests that a complex is formed by vertical stacking or plane-to-plane stacking. The same results were obtained for benzoic acid-d5.

Microporous metal organic framework [M2(hfipbb)2(ted)] (M=Zn, Co; H2hfipbb=4,4-(hexafluoroisopropylidene)-bis(benzoic acid); ted=triethylenediamine): Synthesis, structure analysis, pore characterization, small gas adsorption and CO2/N2 separation properties

Science.gov (United States)

Xu, William W.; Pramanik, Sanhita; Zhang, Zhijuan; Emge, Thomas J.; Li, Jing

2013-04-01

Carbon dioxide is a greenhouse gas that is a major contributor to global warming. Developing methods that can effectively capture CO2 is the key to reduce its emission to the atmosphere. Recent research shows that microporous metal organic frameworks (MOFs) are emerging as a promising family of adsorbents that may be promising for use in adsorption based capture and separation of CO2 from power plant waste gases. In this work we report the synthesis, crystal structure analysis and pore characterization of two microporous MOF structures, [M2(hfipbb)2(ted)] (M=Zn (1), Co (2); H2hfipbb=4,4-(hexafluoroisopropylidene)-bis(benzoic acid); ted=triethylenediamine). The CO2 and N2 adsorption experiments and IAST calculations are carried out on [Zn2(hfipbb)2(ted)] under conditions that mimic post-combustion flue gas mixtures emitted from power plants. The results show that the framework interacts with CO2 strongly, giving rise to relatively high isosteric heats of adsorption (up to 28 kJ/mol), and high adsorption selectivity for CO2 over N2, making it promising for capturing and separating CO2 from CO2/N2 mixtures.

Different Anthocyanin Profiles of the Skin and the Pulp of Yan73 (Muscat Hamburg × Alicante Bouschet Grape Berries

Directory of Open Access Journals (Sweden)

Chang-Qing Duan

2010-03-01

Full Text Available Yan73 is a “teinturier” red wine variety cultivated in China and used in winemaking to strengthen red wine color. Here, the anthocyanin profile in both the skin and pulp of this grape variety was analyzed by HPLC-MS. The results showed that 18 anthocyanins were detected in both the skin and the pulp, and pelargonidin-3-O-glucoside, an anthocyanin compound hardly detected in most other Vitis viniferaberries, was found. However, the contents of individual anthocyanins in the skin and the pulp were significantly different. Compared with the skin, the pulp exhibited much lower ratio of 3’,5’-substituted to 3’-substituted anthocyanins and much higher ratio of methoxylation of anthocyanin B-ring to non methoxylation, and with regard to the aromatic acylated and aliphatic acylated anthocyanins, both their contents in the skin are higher than in the pulp. The findings will provide some new insight for the tissue-specific expression and regulation of the genes involving in anthocyanin biosynthesis in grape berries.

Aligning protein sequence and analysing substitution pattern using ...

Indian Academy of Sciences (India)

Prakash

Aligning protein sequences using a score matrix has became a routine but valuable method in modern biological ..... the amino acids according to their substitution behaviour ...... which may cause great change (e.g. prolonging the helix) in.

Reactivity of lignin and lignin models towards UV-assisted peroxide

International Nuclear Information System (INIS)

Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

1997-01-01

The comparative reactivities of a series of guaiacyl and syringyl lignin model compounds and their methylated analogues towards alkaline peroxide and UV-alkaline peroxide were investigated. The overall reaction was followed by monitoring the reduction of the substrate as a function of time, and in every case, the reaction showed pseudo-first-order kinetics. The reaction rates of most lignin models having identical sidechains with alkaline peroxide and with UV-alkaline peroxide were in the order syringyl guaiacyl 3,4,5-trimethoxyphenyl veratryl. Thus phenols react faster than their methyl ethers, and an extra ortho methoxyl group promotes the reaction. Lignin models possessing electron-donating sidechains had generally higher reaction rates than those with electron-withdrawing sidechains. The reaction rates of the series of benzoic acids were 2-4 times higher at pH 11 than at pH 5. UV-peroxide degradation of a eucalypt kraft lignin was faster than that of a pine kraft lignin, and degradation was 1.4-1.6 times faster at pH 11 than at pH 5. The data are consistent with the formation of higher amounts of reactive radicals under alkaline conditions, and aromatic rings with greater electronegativities promoting reactions with the radicals

A single amino acid substitution in the S1 and S2 Spike protein domains determines the neutralization escape phenotype of SARS-CoV.

Science.gov (United States)

Mitsuki, Yu-ya; Ohnishi, Kazuo; Takagi, Hirotaka; Oshima, Masamichi; Yamamoto, Takuya; Mizukoshi, Fuminori; Terahara, Kazutaka; Kobayashi, Kazuo; Yamamoto, Naoki; Yamaoka, Shoji; Tsunetsugu-Yokota, Yasuko

2008-07-01

In response to SARS-CoV infection, neutralizing antibodies are generated against the Spike (S) protein. Determination of the active regions that allow viral escape from neutralization would enable the use of these antibodies for future passive immunotherapy. We immunized mice with UV-inactivated SARS-CoV to generate three anti-S monoclonal antibodies, and established several neutralization escape mutants with S protein. We identified several amino acid substitutions, including Y442F and V601G in the S1 domain and D757N and A834V in the S2 region. In the presence of each neutralizing antibody, double mutants with substitutions in both domains exhibited a greater growth advantage than those with only one substitution. Importantly, combining two monoclonal antibodies that target different epitopes effected almost complete suppression of wild type virus replication. Thus, for effective passive immunotherapy, it is important to use neutralizing antibodies that recognize both the S1 and S2 regions.

Acides gras inhabituels des organismes marins : une illustration de la biodiversité moléculaire marine

Directory of Open Access Journals (Sweden)

Barnathan Gilles

2010-07-01

Full Text Available In addition to the common polyunsaturated fatty acids (FA such as those of the n-3 and n-6 series with major interest in health and nutrition, marine organisms (invertebrates and algae produce unique FA including branched, methoxylated, halogenated, acetylenic and non-methylene-interrupted structures. The biosynthetic pathways, and the structural and functional roles of these uncommon FA are often not yet known. This short overview wishes to be an outline on the particular FA classes possessing uncommon structures, especially those of increasing interest regarding their promising biological activities.

The occurrence of 2-hydroxy-6-methoxybenzoic acid methyl ester in Securidaca longepedunculata Fresen root bark

Directory of Open Access Journals (Sweden)

Lognay G.

2000-01-01

Full Text Available As part of our ongoing search for natural fumigants from Senegalese plants, we have investigated Securicicidaca longepedunculata root barks and demonstrated that 2-hydroxy-benzoic acid methyl ester (methyl salicylate, I is responsible of their biocide effect against stored grain insects. A second unknown apparented product, II has been systematically observed in all analyzed samples. The present paper describes the identification of this molecule. The analytical investigations including GCMS, GLC and 1H-NMR. spectrometry led to the conclusion that II corresponds to the 2-hydroxy-6-methoxybenzoic acid methyl ester.

NCA nucleophilic radiofluorination on substituted benzaldehydes for the preparation of [18F]fluorinated aromatic amino acids

International Nuclear Information System (INIS)

Wadsak, Wolfgang; Wirl-Sagadin, Barbara; Mitterhauser, Markus; Mien, Leonhard-Key; Ettlinger, Dagmar E.; Keppler, Bernhard K.; Dudczak, Robert; Kletter, Kurt

2006-01-01

Nucleophilic aromatic substitution is a challenging task in radiochemistry. Therefore, a thorough evaluation and optimisation of this step is needed to provide a satisfactory tool for the routine preparation of [ 18 F]fluorinated aromatic amino acids. Two methods, already proposed elsewhere, were evaluated and improved. The yields for the radiofluorination were increased whereas activity loss during solid phase extraction was observed. Radiochemical yields for the two methods were 92.7±5.5% (method 1) and 92.1±12.3% (method 2) for conversion and 11.1±2.8% (method 1) and 34.8±0.6% (method 2) for purification, respectively. In total, we demonstrate an optimised method for the preparation of this important class of [ 18 F]fluorinated synthons for PET

Spontaneous arylation of activated carbon from aminobenzene organic acids as source of diazonium ions in mild conditions

International Nuclear Information System (INIS)

Lebègue, Estelle; Brousse, Thierry; Gaubicher, Joël; Cougnon, Charles

2013-01-01

Activated carbon products modified with benzoic, benzenesulfonic and benzylphosphonic acid groups were prepared by spontaneous reduction of aryldiazonium ions in situ generated in water from the corresponding aminobenzene organic acids without addition of an external acid. Electrochemistry and NMR studies show that the advancement of the diazotization reaction depends both on the acidity and the electronic effect of the organic acid substituent, giving a mixture of diazonium, amine and triazene functionalities. Carbon products prepared by reaction of activated carbon Norit with 4-aminobenzenecarboxylic acid, 4-aminobenzenesulfonic acid and (4-aminobenzyl)phosphonic acid were analyzed by chemical elemental analysis and X-ray photoelectron spectroscopy experiments. Results show that this strategy is well suited for the chemical functionalization, giving a maximized grafting yield due to a chemical cooperation of amine and diazonium functionalities

Amino acid substitutions affecting aspartic acid 605 and valine 606 decrease the interaction strength between the influenza virus RNA polymerase PB2 '627' domain and the viral nucleoprotein.

Science.gov (United States)

Hsia, Ho-Pan; Yang, Yin-Hua; Szeto, Wun-Chung; Nilsson, Benjamin E; Lo, Chun-Yeung; Ng, Andy Ka-Leung; Fodor, Ervin; Shaw, Pang-Chui

2018-01-01

The influenza virus RNA genome is transcribed and replicated in the context of the viral ribonucleoprotein (vRNP) complex by the viral RNA polymerase. The nucleoprotein (NP) is the structural component of the vRNP providing a scaffold for the viral RNA. In the vRNP as well as during transcription and replication the viral polymerase interacts with NP but it is unclear which parts of the polymerase and NP mediate these interactions. Previously the C-terminal '627' domain (amino acids 538-693) of PB2 was shown to interact with NP. Here we report that a fragment encompassing amino acids 146-185 of NP is sufficient to mediate this interaction. Using NMR chemical shift perturbation assays we show that amino acid region 601 to 607 of the PB2 '627' domain interacts with this fragment of NP. Substitutions of these PB2 amino acids resulted in diminished RNP activity and surface plasmon resonance assays showed that amino acids D605 was essential for the interaction with NP and V606 may also play a partial role in the interaction. Collectively these results reveal a possible interaction surface between NP and the PB2 subunit of the RNA polymerase complex.

A Strategy for Simultaneous Isolation of Less Polar Ginsenosides, Including a Pair of New 20-Methoxyl Isomers, from Flower Buds of Panax ginseng

Directory of Open Access Journals (Sweden)

Sha-Sha Li

2017-03-01

Full Text Available The present study was designed to simultaneously isolate the less polar ginsenosides from the flower buds of Panax ginseng (FBPG. Five ginsenosides, including a pair of new 20-methoxyl isomers, were extracted from FBPG and purified through a five-step integrated strategy, by combining ultrasonic extraction, Diaion Hp-20 macroporous resin column enrichment, solid phase extraction (SPE, reversed-phase high-performance liquid chromatography (RP-HPLC analysis and preparation, and nuclear magnetic resonance (NMR analysis. The quantification of the five ginsenosides was also discussed by a developed method with validations within acceptable limits. Ginsenoside Rg5 showed content of about 1% in FBPG. The results indicated that FBPG might have many different ginsenosides with diverse chemical structures, and the less polar ginsenosides were also important to the quality control and standardization of FBPG.

Quinolone resistance-associated amino acid substitutions affect enzymatic activity of Mycobacterium leprae DNA gyrase.

Science.gov (United States)

Yamaguchi, Tomoyuki; Yokoyama, Kazumasa; Nakajima, Chie; Suzuki, Yasuhiko

2017-07-01

Quinolones are important antimicrobials for treatment of leprosy, a chronic infectious disease caused by Mycobacterium leprae. Although it is well known that mutations in DNA gyrase are responsible for quinolone resistance, the effect of those mutations on the enzymatic activity is yet to be studied in depth. Hence, we conducted in vitro assays to observe supercoiling reactions of wild type and mutated M. leprae DNA gyrases. DNA gyrase with amino acid substitution Ala91Val possessed the highest activity among the mutants. DNA gyrase with Gly89Cys showed the lowest level of activity despite being found in clinical strains, but it supercoiled DNA like the wild type does if applied at a sufficient concentration. In addition, patterns of time-dependent conversion from relaxed circular DNA into supercoiled DNA by DNA gyrases with clinically unreported Asp95Gly and Asp95Asn were observed to be distinct from those by the other DNA gyrases.

Synthesis of meta-substituted monodentate phosphinite ligands and ...

Indian Academy of Sciences (India)

SATEJ S DESHMUKH

from organic synthesis, phosphinite ligands find appli- cations in a variety of ... thesis of meta-substituted phosphinite ligands is rarely reported.18 This is most ... 1.9 μm; mobile phase used, 90% methanol + 10% water +. 0.1% formic acid) ...

A microwave-catalyzed rapid, efficient and ecofriendly synthesis of substituted pyrazol-5-ones

Directory of Open Access Journals (Sweden)

RAHUL P. GAVANDE

2003-10-01

Full Text Available A series of 1-(3,4-dihydro-3-oxo-2H-1,4-benzoxazine-2-carbonyl-3-methyl-4-(substituted phenylhydrazono-2-pyrazolin-5-ones have been synthesized by the reaction of 2H-3,4-dihydro-3-oxo-1,4-benzoxazine-2-carboxylic acid hydrazide with substituted acetoacetic ester derivatives using acetic acid as solvent under microwave irradiation (MWI, as well as by conventional methods. The reaction rate is enhanced tremendously and the yields are improved under MWI as compared to conventional methods.

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

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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.

LASER BIOLOGY AND MEDICINE: Application of laser fluorimetry for determining the influence of a single amino-acid substitution on the individual photophysical parameters of a fluorescent form of a fluorescent protein mRFP1

Science.gov (United States)

Banishev, A. A.; Vrzheshch, E. P.; Shirshin, E. A.

2009-03-01

Individual photophysical parameters of the chromophore of a fluorescent protein mRFP1 and its two mutants (amino-acid substitution at position 66 - mRFP1/ Q66C and mRFP1/Q66S proteins) are determined. For this purpose, apart from conventional methods of fluorimetry and spectrophotometry, nonlinear laser fluorimetry is used. It is shown that the individual extinction coefficients of the chromophore of proteins correlate (correlation coefficient above 0.9) with the volume of the substituted amino-acid residue at position 66 (similar to the positions of the absorption, fluorescence excitation and emission maxima).

Substituted N-Phenylpyrazine-2-carboxamides, Their Synthesis and Evaluation as Herbicides and Abiotic Elicitors

Directory of Open Access Journals (Sweden)

Katarína Kráľová

2007-12-01

Full Text Available The condensation of substituted pyrazine-2-carboxylic acid chlorides with ring-substituted anilines yielded five substituted pyrazine-2-carboxylic acid amides. Thesynthesis, and analytical, lipophilicity and biological data of the newly synthesizedcompounds are presented in this paper. The photosynthesis inhibition, antialgal activityand the effect of a series of pyrazine derivatives as abiotic elicitors on the accumulation offlavonoids in a callus culture of Ononis arvensis (L. were investigated. The most activeinhibitor of the oxygen evolution rate in spinach chloroplasts was 6-chloro-pyrazine-2-carboxylic acid (3-iodo-4-methylphenyl-amide (2, IC50 = 51.0 μmol·L-1. The highestreduction of chlorophyll content in Chlorella vulgaris was found for 5-tert-butyl-N-(4-chloro-3-methylphenyl-pyrazine-2-carboxamide (3, IC50 = 44.0 μmol·L-1. The maximalflavonoid production (about 900% was reached after a twelve-hour elicitation processwith 6-chloropyrazine-2-carboxylic acid (3-iodo-4-methylphenyl-amide (2.

Identification of Lactic Acid Bacteria from Chili Bo, a Malaysian Food Ingredient

Science.gov (United States)

Leisner, Jørgen J.; Pot, Bruno; Christensen, Henrik; Rusul, Gulam; Olsen, John E.; Wee, Bee Wah; Muhamad, Kharidah; Ghazali, Hasanah M.

1999-01-01

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28°C with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg−1 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682. PMID:9925588

Antimicrobial activity against Porphyromonas gingivalis and mechanism of action of the cationic octadecapeptide AmyI-1-18 and its amino acid-substituted analogs.

Science.gov (United States)

Taniguchi, Masayuki; Ochiai, Akihito; Takahashi, Kiyoshi; Nakamichi, Shun-Ichi; Nomoto, Takafumi; Saitoh, Eiichi; Kato, Tetsuo; Tanaka, Takaaki

2016-12-01

The antimicrobial peptide AmyI-1-18 is a cationic α-helical octadecapeptide derived from α-amylase in rice (Oryza sativa L. japonica) that contains four cationic amino acid residues (two arginines and two lysines). To enhance the antibacterial activity of AmyI-1-18 against Porphyromonas gingivalis (a bacterium associated with periodontal disease), we synthesized 12 analogs bearing substitutions with alanine, leucine, and/or arginine that were designed based on helical wheel projections and investigated their antibacterial properties. The antibacterial properties of four analogs bearing substitution of a single arginine or lysine with alanine were almost similar to those of AmyI-1-18, suggesting that the antibacterial properties depend on the presence of three cationic amino acid residues. Of three single arginine-substituted analogs, AmyI-1-18(G12R) exhibited an antibacterial activity 2.8-fold higher [50% growth-inhibitory concentration (IC 50 ): 4.6 μM] than that of AmyI-1-18 (IC 50 : 13 μM). Likewise, the antibacterial properties of two single leucine-substituted analogs were significantly enhanced; in particular, AmyI-1-18(N3L) exhibited an antibacterial activity (IC 50 : 2.5 μM) 5.2-fold higher than that of AmyI-1-18. The hemolytic activity of AmyI-1-18(N3L) against mammalian red blood cells was low (2% at 50 μM). A membrane-depolarization assay using a membrane potential-sensitive fluorescent dye revealed that, similar to AmyI-1-18, the antibacterial activity of AmyI-1-18(N3L) was not dependent on its membrane-disrupting activity. Our results demonstrate that the antibacterial properties of AmyI-1-18 against P. gingivalis are significantly improved, without a significant increase in hemolytic activity, by replacing asparagine with leucine at position 3. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

No evidence for association of ataxia-telangiectasia mutated gene T2119C and C3161G amino acid substitution variants with risk of breast cancer

International Nuclear Information System (INIS)

Spurdle, Amanda B; Hopper, John L; Chen, Xiaoqing; McCredie, Margaret RE; Giles, Graham G; Newman, Beth; Chenevix-Trench, Georgia; Khanna, KumKum

2002-01-01

There is evidence that certain mutations in the double-strand break repair pathway ataxia-telangiectasia mutated gene act in a dominant-negative manner to increase the risk of breast cancer. There are also some reports to suggest that the amino acid substitution variants T2119C Ser707Pro and C3161G Pro1054Arg may be associated with breast cancer risk. We investigate the breast cancer risk associated with these two nonconservative amino acid substitution variants using a large Australian population-based case–control study. The polymorphisms were genotyped in more than 1300 cases and 600 controls using 5' exonuclease assays. Case–control analyses and genotype distributions were compared by logistic regression. The 2119C variant was rare, occurring at frequencies of 1.4 and 1.3% in cases and controls, respectively (P = 0.8). There was no difference in genotype distribution between cases and controls (P = 0.8), and the TC genotype was not associated with increased risk of breast cancer (adjusted odds ratio = 1.08, 95% confidence interval = 0.59–1.97, P = 0.8). Similarly, the 3161G variant was no more common in cases than in controls (2.9% versus 2.2%, P = 0.2), there was no difference in genotype distribution between cases and controls (P = 0.1), and the CG genotype was not associated with an increased risk of breast cancer (adjusted odds ratio = 1.30, 95% confidence interval = 0.85–1.98, P = 0.2). This lack of evidence for an association persisted within groups defined by the family history of breast cancer or by age. The 2119C and 3161G amino acid substitution variants are not associated with moderate or high risks of breast cancer in Australian women

Selenomethionine substitution of orotidine-5-monophosphate decarboxylase causes a change in crystal contacts and space group

DEFF Research Database (Denmark)

Poulsen, Jens-Christian Navarro; Harris, Pernille; Jensen, Kaj Frank

2001-01-01

with the inhibitor 1-(5'-phospho- -D-ribofuranosyl)barbituric acid crystallizes under similar conditions as the native enzyme. In contrast to the native enzyme, where the crystals belong to the orthorhombic space group P212121, the SeMet-substituted enzyme crystallizes in the monoclinic space group P21......-wavelength anomalous dispersion technique, both native and SeMet-substituted proteins have been produced and purified. During the production of SeMet ODCase, it was observed that SeMet was the only amino acid that it was necessary to add to the defined medium during expression. SeMet-substituted ODCase in complex...

1-Hydroxyethyl-2-Substituted Phenoxymethyl Benzimidazoles: Synthesis and Crystal Structures

International Nuclear Information System (INIS)

Wu, J.; Wang, Z.; Gu, H.; Chen, W.; Zhao, L.; Zhao, C.

2016-01-01

Five novel 1-hydroxyethyl-2-substituted phenoxymethyl benzimidazoles c1-c5 were successfully synthesized by a three-step route. Firstly, five substituted phenoxymethyl acids a1-a5 were prepared by the O-carboxymethylation reaction of the starting substituted phenols under microwave irradiation. Then, these compounds reacted with o-phenylendiamine to get the key intermediates 2-substituted phenoxymethyl benzimidazoles b1-b5. At last, the target compounds were synthesized by the N-hydroxyethylation reaction of b1-b5 with 2-chloroethyl alcohol through the solid-liquid phase transfer catalysis method, where tetrabutyl ammonium bromide (TBAB) was used as the catalyst. The structures of the target compounds were well characterized and verified by elemental analysis, MS, IR, 1H NMR, 13C NMR and single crystal X-ray diffraction analysis. (author)

Influence of variation in mobile phase pH and solute pK(a) with the change of organic modifier fraction on QSRRs of hydrophobicity and RP-HPLC retention of weakly acidic compounds.

Science.gov (United States)

Han, Shu-ying; Liang, Chao; Zou, Kuan; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2012-11-15

The variation in mobile phase pH and ionizable solute dissociation constant (pK(a)) with the change of organic modifier fraction in hydroorganic mobile phase has seemingly been a troublesome problem in studies and applications of reversed phase high performance liquid chromatography (RP-HPLC). Most of the early studies regarding the RP-HPLC of acid-base compounds have to measure the actual pH of the mixed mobile phase rigorously, sometimes bringing difficulties in the practices of liquid chromatographic separation. In this paper, the effect of this variation on the apparent n-octanol/water partition coefficient (K(ow)″) and the related quantitative structure-retention relationship (QSRR) of logK(ow)″ vs. logk(w), the logarithm of retention factor of analytes in neat aqueous mobile phases, was investigated for weakly acidic compounds. This QSRR is commonly used as a classical method for K(ow) measurement by RP-HPLC. The theoretical and experimental derivation revealed that the variation in mobile phase pH and solute pK(a) will not affect the QSRRs of acidic compounds. This conclusion is proved to be suitable for various types of ion-suppressors, i.e., strong acid (perchloric acid), weak acid (acetic acid) and buffer salt (potassium dihydrogen phosphate/phosphoric acid, PBS). The QSRRs of logK(ow)″ vs. logk(w) were modeled by 11 substituted benzoic acids using different types of ion-suppressors in a binary methanol-water mobile phase to confirm our deduction. Although different types of ion-suppressor all can be used as mobile phase pH modifiers, the QSRR model obtained by using perchloric acid as the ion-suppressor was found to have the best result, and the slightly inferior QSRRs were obtained by using acetic acid or PBS as the ion-suppressor. Copyright © 2012 Elsevier B.V. All rights reserved.

The structural features of hemicelluloses dissolved out at different cooking stages of active oxygen cooking process.

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Shi, Jianbin; Yang, Qiulin; Lin, Lu

2014-04-15

This work described the morphologic changes of corn stalk and the structural characterization of its hemicelluloses dissolved in yellow liquor at different cooking stages. The results showed that active oxygen cooking process was an efficient method to depolymerize the corn stalk into cellulose, hemicelluloses, and lignin as a pretreatment of biomass conversion. This cooking process can also be divided into three phases: bulk delignification, extended delignification, and residual delignification. During the heating-up period 57.67% of hemicelluloses and 62.31% of lignin were removed from the raw material. However, only 15% of hemicelluloses and 23.21% of lignin were removed during at temperature' period. The hemicelluloses from the corn stalk and yellow liquor were composed of (1→4)-β-D-xylopyranose backbones substituted with α-l-arabinofuranosyl, 4-O-methyl-α-D-glucuronic acid, and some methoxyl residues. The backbones of hemicelluloses were gradually cleaved during the cooking process. The acetyl groups substituted with xylopyranosyl residues were completely cleaved during the cooking process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Separation of aliphatic carboxylic acids and benzenecarboxylic acids by ion-exclusion chromatography with various cation-exchange resin columns and sulfuric acid as eluent.

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Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae-Jeong; Lee, Kwang-Pill

2003-05-16

The application of various hydrophilic cation-exchange resins for high-performance liquid chromatography (sulfonated silica gel: TSKgel SP-2SW, carboxylated silica gel: TSKgel CM-2SW, sulfonated polymethacrylate resin: TSKgel SP-5PW, carboxylated polymethacrylate resins: TSKgel CM-5PW and TSKgel OA-Pak A) as stationary phases in ion-exclusion chromatography for C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, butyric, isovaleric, valeric, isocaproic, caproic, 2-methylhexanoic and heptanoic acids) and benzenecarboxylic acids (pyromellitic, trimellitic, hemimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic, salicylic acids and phenol) was carried out using diluted sulfuric acid as the eluent. Silica-based cation-exchange resins (TSKgel SP-2SW and TSKgel CM-2SW) were very suitable for the ion-exclusion chromatographic separation of these benzenecarboxylic acids. Excellent simultaneous separation of these benzenecarboxylic acids was achieved on a TSKgel SP-2SW column (150 x 6 mm I.D.) in 17 min using a 2.5 mM sulfuric acid at pH 2.4 as the eluent. Polymethacrylate-based cation-exchange resins (TSKgel SP-5PW, TSKgel CM-5PW and TSKgel OA-Pak A) acted as advanced stationary phases for the ion-exclusion chromatographic separation of these C1-C7 aliphatic carboxylic acids. Excellent simultaneous separation of these C1-C7 acids was achieved on a TSKgel CM-5PW column (150 x 6 mm I.D.) in 32 min using a 0.05 mM sulfuric acid at pH 4.0 as the eluent.

Synthesis, Spectral and Antimicrobial Studies of Some N(2)-Substituted Tetrahydroindazoles

International Nuclear Information System (INIS)

Amirthaganesan, Shanmugasundaram; Aridoss, Gopalakrishnan; Park, Keun Soo; Lim, Kwon Taek; Jeong, Yeon Tae

2010-01-01

A series of N(2)-benzothiazolyl substituted tetrahydroindazoles has been synthesized via cyclic β keto esters. Optimum reaction condition was found as acidic toluene and effect of higher acidity towards substituted hydrazines in situ was described. Synthesized compounds have been achieved as single isomer and characterized by using 1D and 2D NMR spectral reports. Antimicrobial screening was carried out for the synthesized compounds along with a series of N(2)-pyridyl tetrahydroindazoles. 1 The results of the in vitro antimicrobial screening studies revealed that compounds 13, 16 against Staphylococcus aureus, 11 against Escherichia coli, 10-12, 16 against Pseudomonas aeruginosa and 12 against Klebsiella pneumoniae recorded almost two-fold better activity compared to the standard drug used

Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

Science.gov (United States)

Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

2014-07-01

The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite. © 2013 Wiley Periodicals, Inc.

The Synthesis of Substituted Piperazine-cholesterol Conjugates for ...

African Journals Online (AJOL)

A small library of cholesterol-piperazine conjugates were synthesized by the reaction of cholesteryl chloroformate with a set of substituted piperazines in dichloromethane at room temperature. The conjugates, all obtained in good to excellent yields, were synthesized to be key components of nucleic acid transfection ...

Identification of the free phenolic profile of Adlay bran by UPLC-QTOF-MS/MS and inhibitory mechanisms of phenolic acids against xanthine oxidase.

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