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1

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2008-04-01 2008-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2008-04-01

2

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2012-04-01 2012-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2012-04-01

3

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2004-04-01 2004-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2004-04-01

4

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2011-04-01 2011-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2011-04-01

5

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2005-04-01 2005-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2005-04-01

6

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2006-04-01 2006-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2006-04-01

7

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2007-04-01 2007-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid...

2007-04-01

8

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2009-04-01 2009-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7...

2009-04-01

9

21 CFR 184.1021 - Benzoic acid.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 2009-04-01 true Benzoic acid. 184.1021 Section 184.1021 Food and...Specific Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7...

2010-01-01

10

[Pretreatment of benzoic acid wastewater].  

PubMed

The benzoic acid wastewater produced from toluene by liquid-phase oxidation is one of the difficult wastewater to treat because of multi-component, high CODcr value (20,000-100,000 mg/L) and nonbiodegradability. A pretreatment way of this wastewater by extraction based on chemical complexation was carried out, and tributyl phosphate (TBP), trialkylamine (7301) and trialkyphosphine oxide (TRPO) were used as complexing agent with n-octanol, kerosene as cosolvent and diluent respectively. Results showed that benzoic acid was recovery successfully and the CODcr value of wastewater was reduced to 1/6 of the initial value through multi-stages cross-flow extraction. Back-extraction was quite easy and the solvent could be reused. PMID:11769235

Li, Z; Qin, W; Huang, Y; Zhang, H; Dai, Y

2001-09-01

11

40 CFR 721.1680 - Substituted benzoic acid (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted benzoic acid (generic). 721.1680 Section...Substances § 721.1680 Substituted benzoic acid (generic). (a) Chemical...identified generically as substituted benzoic acid (PMN P-01-423) is...

2013-07-01

12

Capillary Electrophoresis of Substituted Benzoic Acids  

ERIC Educational Resources Information Center

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

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

2005-01-01

13

Photodissociation dynamics of benzoic acid  

SciTech Connect

The photodissociation of benzoic acid at 193 and 248 nm was investigated using multimass ion imaging techniques. Three dissociation channels were observed at 193 nm: (1) C{sub 6}H{sub 5}COOH{yields}C{sub 6}H{sub 5}+COOH, (2) C{sub 6}H{sub 5}COOH{yields}C{sub 6}H{sub 5}CO+OH, and (3) C{sub 6}H{sub 5}COOH{yields}C{sub 6}H{sub 6}+CO{sub 2}. Only channels, (2) and (3), were observed at 248 nm. Comparisons of the ion intensities and photofragment translational energy distributions with the potential energies obtained from ab initio calculations and the branching ratios obtained from the Rice-Ramsperger-Kassel-Marcus theory suggest that the dissociation occurs on many electronic states.

Dyakov, Yuri A.; Bagchi, Arnab; Lee, Yuan T.; Ni, Chi-Kung [Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan (China)

2010-01-07

14

40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).  

Code of Federal Regulations, 2010 CFR

... false Disubstituted benzoic acid, alkali metal salt (generic). 721...10098 Disubstituted benzoic acid, alkali metal salt (generic). ...generically as disubstituted benzoic acid, alkali metal salt (PMN...

2009-07-01

15

40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).  

Code of Federal Regulations, 2010 CFR

... false Disubstituted benzoic acid, alkali metal salt (generic). 721...10098 Disubstituted benzoic acid, alkali metal salt (generic). ...generically as disubstituted benzoic acid, alkali metal salt (PMN...

2010-07-01

16

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. (a...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane...

2009-07-01

17

40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. (a...2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane...

2010-07-01

18

Benzoic acid degradation of polyacrylonitrile fibers  

NASA Technical Reports Server (NTRS)

The reactions of polyacrylonitrile (PAN) fibers in the presence of benzoic acid have been studied. Polyacrylonitrile fibers oxidize more readily in the presence of benzoic acid than in air at temperatures in the range of 170 C. The product decreased in solubility with extent of reaction. Gel permeation chromatography of the soluble fraction showed change in polydispersity. The insoluble product exhibited differences in weight loss as a function of decomposition temperature compared to PAN fibers. Infrared analyses of the fiber product showed absorption peaks similar to air-oxidized PAN. High-energy photoelectron spectral analysis showed a carbon-rich surface which contained oxygen and nitrogen. An air oxidized sample of fiber contained more oxygen at the surface than a fiber treated first with benzoic acid and then air oxidized.

Varma, D. S.; Needles, H. L.; Cagliostro, D. E.

1981-01-01

19

[Pretreatment and resource utilization of industrial effluent with benzoic acid].  

PubMed

Extraction equilibrium of benzoic acid were studied using 20%, 30% and 50% tributyl phosphate (TBP) in kerosene, 1-octanol and toluene as the extractants, to investigate the efficient method of recovering benzoic and acetic acid in the industrial effluent and meeting the requirement of the terminal wastewater treatment. The CODCr value in residual phase and the recovery of benzoic acid in various extractants were measured. The results showed that the recovery of benzoic acid was closed to 100% with 50% TBP/kerosene system, and depended on the polarity of extractant for pure solvent system. The recovery with 1-octanol was equivalent to the one with 30% TBP. The CODCr value in the residual phase depended on the CODCr value from benzoic acid and the solubility of extractant, which does not depend on the benzoic acid concentration in the residue phase apparently, and shown 50% TBP approximately equal to 30% TBP > 1-octanol > 20% TBP > toluene. Meanwhile, the profitable diagram of pretreatment of industrial effluent with benzoic acid was suggested, i.e. firstly, extract benzoic acid with toluene and return the toluene to the benzoic acid reactor, then, extract acetic acid with trialkylphosphine oxide and back-extract the acetic acid with CaO or MgO to produce calcium magnesium acetate. PMID:15515941

Qin, Wei; Wang, Sheng; Mei, Fan; Lin, Yi; Dai, You-yuan

2004-07-01

20

A Kinetic Study on Benzoic Acid Pungency and Sensory Attributes of Benzoic Acid  

Microsoft Academic Search

Aqueous solutions of benzoic acid (BA) were evaluated by two methods: (i) sensory profile: a descriptive test of sensory attributes combined with semiquantitative analysis; and (ii) pungency intensity measures as a function of time: a computerized recording using specific software. Kinetic parameters evaluated were maximal intensity (IMAX), total time of pungency (Ttot), rates of increase (V1) and decrease (V2), half-life

Matilde E. Otero-Losada

1999-01-01

21

40 CFR 721.1705 - Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Benzoic acid, 3-amino-, diazotized, coupled with...Substances § 721.1705 Benzoic acid, 3-amino-, diazotized, coupled with...generically identified as benzoic acid, 3-amino-, diazotized, coupled...

2013-07-01

22

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol. 721...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol. (a...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol...

2009-07-01

23

40 CFR 721.10110 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol. 721...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol. (a...2-ethyl-, mixed diesters with benzoic acid and neopentlyl glycol...

2010-07-01

24

40 CFR 721.1705 - Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Benzoic acid, 3-amino-, diazotized, coupled...Chemical Substances § 721.1705 Benzoic acid, 3-amino-, diazotized, coupled...substance generically identified as benzoic acid, 3-amino-, diazotized,...

2010-07-01

25

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol. 721...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol. (a...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol...

2009-07-01

26

40 CFR 721.1705 - Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid...  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Benzoic acid, 3-amino-, diazotized, coupled...Chemical Substances § 721.1705 Benzoic acid, 3-amino-, diazotized, coupled...substance generically identified as benzoic acid, 3-amino-, diazotized,...

2009-07-01

27

40 CFR 721.10111 - Hexanoic acid, 2-ethyl-, mixed diesters with benzoic acid and diethylene glycol.  

Code of Federal Regulations, 2010 CFR

...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol. 721...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol. (a...2-ethyl-, mixed diesters with benzoic acid and diethylene glycol...

2010-07-01

28

40 CFR 721.10380 - Benzoic acid, 3-amino-2-mercapto-.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Benzoic acid, 3-amino-2-mercapto-. 721.10380...Substances § 721.10380 Benzoic acid, 3-amino-2-mercapto-. (a) Chemical...substance identified as benzoic acid, 3-amino-2-mercapto- (PMN...

2013-07-01

29

40 CFR 721.10399 - Benzoic acid azo-substituted pyridine (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Benzoic acid azo-substituted pyridine (generic...Chemical Substances § 721.10399 Benzoic acid azo-substituted pyridine (generic...substance identified generically as benzoic acid azo-substituted...

2013-07-01

30

40 CFR 721.10098 - Disubstituted benzoic acid, alkali metal salt (generic).  

Code of Federal Regulations, 2011 CFR

...Disubstituted benzoic acid, alkali metal salt (generic). 721.10098 Section 721...Disubstituted benzoic acid, alkali metal salt (generic). (a) Chemical substance...disubstituted benzoic acid, alkali metal salt (PMN P-03-643) is subject to...

2011-07-01

31

The anaerobic decomposition of benzoic acid during methane fermentation  

Microsoft Academic Search

Anaerobic rupture of the benzoic acid ring was investigated. Carbon 4 was converted primarily to carbon dioxide. Following ring rupture during methane fermentation, propanoic acid is an intermediate, and carbon 4 of benzoate becomes its carboxyl.

L. R. Fina; R. L. Bridges; T. H. Coblentz; F. F. Roberts

1978-01-01

32

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

SciTech Connect

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

Arceo, Elena; Ellman, Jonathan; Bergman, Robert

2010-05-03

33

Benzoic Acid 2Hydroxylase, a Soluble Oxygenase from Tobacco, Catalyzes Salicylic Acid Biosynthesis  

Microsoft Academic Search

Benzoic acid 2-hydroxylase (BA2H) catalyzes the biosynthesis of salicylic acid from benzoic acid. The enzyme has been partially purified and characterized as a soluble protein of 160 kDa. High-efficiency in vivo labeling of salicylic acid with ^18O_2 suggested that BA2H is an oxygenase that specifically hydroxylates the ortho position of benzoic acid. The enzyme was strongly induced by either tobacco

Jose Leon; Vladimir Shulaev; Nasser Yalpani; Michael A. Lawton; Ilya Raskin

1995-01-01

34

Molecular structures of triethylamine complexes with benzoic and pivalic acids  

Microsoft Academic Search

Dissolution of benzoic or pivalic acid in excess triethylamine followed by crystallization was found to yield single crystals\\u000a of 1: 1 and 1: 2 complexes, respectively. X-ray crystallography have shown that the complex with benzoic acid is an (Et3NH)+(OOCPh)? ion pair, in which the proton is transfered from the acid to the base (N?O 2.629(2) ), and the complex with

M. A. Yakovleva; E. V. Perova; I. S. Kislina; N. B. Librovich; S. E. Nefedov

2010-01-01

35

Structural landscape of the 1 : 1 benzoic acid : isonicotinamide cocrystal.  

PubMed

The acid-pyridine heterosynthon may be used as a "molecular" module to probe the structural landscape of the benzoic acid : isonicotinamide 1 : 1 cocrystal, BA : INA. Experimental structures of 1 : 1 cocrystals of fluorobenzoic acids (FBA) with isonicotinamide (INA) contain this heterosynthon and correspond to high-energy structures of 1 : 1 BA : INA. PMID:24326969

Dubey, Ritesh; Desiraju, Gautam R

2014-02-01

36

Antiparasitic activity of prenylated benzoic acid derivatives from Piper species.  

PubMed

Fractionation of dichloromethane extracts from the leaves of Piper heterophyllum and P. aduncum afforded three prenylated hydroxybenzoic acids, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid, 3-[(2E,6E,10E)-11-carboxy-13-hydroxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl]-4,5-dihydroxybenzoic acid and 3-[(2E,6E,10E)-11-carboxy-14-hydroxy-3,7,15-trimethyl-2,6,10,15-hexadecatetraenyl]-4,5-dihydroxybenzoic acid, along with the known compounds, 4,5-dihydroxy-3-(E,E,E-11-formyl-3,7,15-trimethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid (arieianal), 3,4-dihydroxy-5-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 4-hydroxy-3-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid, 4-hydroxy-3-(3,7-dimethyl-2,6-octadienyl)benzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. Riguera ester reactions and optical rotation measurements established the compounds as racemates. The antiparasitic activity of the compounds were tested against three strains of Leishmania spp., Trypanosoma cruzi and Plasmodium falciparum. The results showed that 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid exhibited potent and selective activity against L. braziliensis (IC(50) 6.5 microg/ml), higher that pentamidine used as control. Moreover, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl- 2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid showed moderate antiplasmodial (IC(50) 3.2 microg/ml) and trypanocidal (16.5 microg/ml) activities, respectively. PMID:19361822

Flores, Ninoska; Jimnez, Ignacio A; Gimnez, Alberto; Ruiz, Grace; Gutirrez, David; Bourdy, Genevieve; Bazzocchi, Isabel L

2009-03-01

37

Determination of benzoic acid, chlorobenzoic acids and chlorendic acid in water  

SciTech Connect

To characterize and conduct treatment studies of a landfill leachate an analysis procedure was required to determine concentrations of benzoic acid, the three isomers of chlorobenzoic acid and chlorendic acid. The title compounds were isolated from acidified (pH 1) water by extraction with methyl t-butyl ether. Analytes were concentrated by back-extracting the ether with 0.1 N sodium hydroxide which was separated and acidified. This solution was analyzed by C[sub 18] reversed-phase HPLC with water/acetonitrile/acetic acid eluent and UV detection at 222 nm. The method has detection limits of 200 [mu]g/L for chlorendic acid and 100 [mu]g/L for benzoic acid and each isomer of chlorobenzoic acid. Validation studies with water which was fortified with the analytes at concentrations ranging from one to ten times detection limits resulted in average recoveries of >95%.

Dietz, E.A.; Cortellucci, N.J.; Singley, K.F. (Occidental Chemical Corp., Grand Island, NY (United States))

1993-01-01

38

Benzoic acid as a natural compound in cultured dairy products and cheese  

Microsoft Academic Search

This review deals with the state of the art of benzoic acid in cultured dairy products and cheese. During fermentation, benzoic acid is produced from hippuric acid, a component of milk naturally present at concentrations of up to 50 mg\\/kg. In smearripened cheese, however, higher benzoic acid concentrations have often been measured on the surface or even inside such cheeses.

R Sieber; U Btikofer; J. O Bosset

1995-01-01

39

QSAR study of the toxicity of benzoic acids to Vibrio fischeri, Daphnia magna and carp  

Microsoft Academic Search

The toxicities of benzoic acids to Vibrio fischeri, Daphnia magna and carp were measured. The results showed that the toxicity to V. fischeri and Daphnia decreased in the order of bromo>chloro>fluoro?aminobenzoic acids. The toxicity of substituted benzoic acids to carp and Daphnia was much lower than that to V. fischeri. The results also showed that the toxicity of benzoic acids

Y. H. Zhao; G. D. Ji; M. T. D. Cronin; J. C. Dearden

1998-01-01

40

40 CFR 721.10202 - Benzoic acid, 4-chloro-2- [(substituted)azo]-, strontium salt (1:1) (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Benzoic acid, 4-chloro-2- [(substituted...Chemical Substances § 721.10202 Benzoic acid, 4-chloro-2- [(substituted...substance identified generically as benzoic acid, 4-chloro-2-...

2013-07-01

41

Uptake of benzoic acid and chloro-substituted benzoic acids by alcaligenes denitrificans BRI 3010 and BRI 6011  

SciTech Connect

The mechanism of uptake of benzoic and 2,4-dichlorobenzoic acid (2,4-DCBA) by Alcaligenes denitrificans BRI 3010 and BRI 6011 and Pseudomonas sp. strain B13, three organisms capable of degrading isomers of chlorinated benzoic acids, was investigated. In all three organisms, uptake of benzoic acid was inducible. For benzoic acid uptake into BRI 3010, monophasic saturation kinetics with apparent K{sub m} and V{sub max} values of 1.4 {mu}M and 3.2 nmol/min/mg of cell dry weight, respectively, were obtained. For BRI 6011, biphasic saturation kinetics were observed, suggesting presence of two uptake systems for benzoic acid with distinct K{sub m} (0.72 and 5.3 {mu}M) and V{sub max} (3.3 and 4.6 nmol/min/mg of cell dry weight) values. BRI 3010 and BRI 6011 accumulated benzoic acid against a concentration gradient by a factor of 8 and 10, respectively. A wide range of structural analogs, at 50-fold excess concentrations, inhibited benzoic acid uptake by BRI 3010 and BRI 6011, whereas with B13, only 3-chlorobenzoic acid was an effective inhibitor. For BRI 3010 and BRI 6011, the inhibition by the structural analogs was not of a competitive nature. Uptake of benzoic acid by BRI 3010 and BRI 6011 was inhibited by KCN, by the protonophore 3,5,3`, 4`-tetrachlorosalicylanilide (TCS), and, for BRI 6011, by anaerobiosis unless nitrate was present, thus indicating that energy was required for the uptake process. Uptake of 2,4-DCBA by BRI 6011 was constitutive and saturation uptake kinetics were not observed. Uptake of 2,4-DCBA by BRI 6011 was inhibited by KCN, TCS, and anaerobiosis even if nitrate was present, but the compound was not accumulated intracellularly against a concentration gradient. Uptake of 2,4-DCBA by BRI 6011 appears to occur by passive diffusion into the cell down its concentration gradient, which is maintained by the intracellular metabolism of the compound. This process could play an important role in the degradation of xenobiotic compounds by microorganisms.

Miguez, C.B.; Ingram, J.M.; MacLeod, R.A. [McGill Univ., Quebec (Canada)] [and others

1995-12-01

42

The biosynthesis of benzoic acid glucosinolate esters in Arabidopsis thaliana  

Microsoft Academic Search

The siliques and seeds of Arabidopsis thaliana accumulate a series of glucosinolates containing an alkyl side chain of varying length with a terminal benzoate ester function. The biosynthesis of these unusual nitrogen- and sulfur-containing natural products was investigated by feeding isotopically-labeled precursors to detached flowering stems. Glucosinolates were extracted, purified and analyzed by tandem mass spectrometry. Phenylalanine and benzoic acid

Gerson Graser; Neil J. Oldham; Paul D. Brown; Ulrike Temp; Jonathan Gershenzon

2001-01-01

43

Studies on the anaerobic degradation of benzoic acid and 2-aminobenzoic acid by a denitrifying Pseudomonas strain  

Microsoft Academic Search

The growth of a denitrifying Pseudomonas strain on benzoic acid and 2-aminobenzoic acid (anthranilic acid) has been studied. The organism grew aerobically on benzoate, 2-aminobenzoate, and gentisate, but not on catechol or protocatechuic acid. These and other findings suggest that aerobic degradation of benzoic acid was via gentisic acid. Under completely anaerobic conditions in the presence of nitrate, benzoate and

K. Ziegler; K. Braun; A. Biickler; G. Fuchs

1987-01-01

44

Substituent effects on the acidity of weak acids. 2. Calculated gas-phase acidities of substituted benzoic acids.  

PubMed

To investigate the origin of substituent effects on the acidity of benzoic acids, the structures of a series of substituted benzoic acids and benzoates have been calculated at the B3LYP/6-311+G* and MP2/6-311+G* theoretical levels. The vibrational frequencies were calculated using B3LYP/6-311+G* and allowed corrections for the change in zero-point energies on ionization, and the change in energy on going from 0 K (corresponding to the calculations) to 298 K. A more satisfactory agreement with the experimental values was obtained by energy calculations at the MP2/ 6-311++G* level using the above structures. The resulting Delta H(acid) values agree very well with the experimental gas-phase acidities. The energies of compounds with pi-electron-accepting or -releasing substituents, rotated to give the transition state geometries, provided rotational barriers that could be compared with those found for the corresponding substituted benzenes. Isodesmic reactions allowed the separate examination of the substituent effects on the energies of the acids and on the anions. Electron-withdrawing groups stabilize the benzoate anions more than they destabilize the benzoic acids. Electron-donating groups stabilize the acids and destabilize the anions by approximately equal amounts. The gas-phase acidities of meta- and para-substituted benzoic acids are linearly related. This is also found for the acidities of substituted phenylacetic acids and benzoic acids. Since direct pi-electron interactions are not possible with the phenylacetic acids, this indicates that the acidities are mainly controlled by a field effect interaction between the charge distribution in the substituted benzene ring and the negative charge of the carboxylate group. The Hammett sigma(M) and sigma(P) values are also linearly related for many small substituents from NO(2) through the halogens and to OH and NH(2). Most of the other substituents fall on a line with a different slope PMID:12098290

Wiberg, Kenneth B

2002-07-12

45

Inhibition of benzoic acid on the polyanilinepolyphenol oxidase biosensor  

Microsoft Academic Search

A polyanilinepolyphenol oxidase (PANIPPO) biosensor for detecting benzoic acid is reported. The biosensor is based on the inhibition of benzoic acid on the biocatalytic activity of the polyphenol oxidase (PPO). The MichaelisMenten constant (k?m) and maximum response current (Imax) in both the absence and presence of benzoic acid are also evaluated. The kinetic analyses show that the inhibition of benzoic

Shengqi Li; Yongyan Tan; Peng Wang; Jinqing Kan

2010-01-01

46

Antimicrobial activity of phenol and benzoic acid derivatives  

Microsoft Academic Search

Vinyl monomers with phenol and benzoic acid as pendant groups were synthesized, and their antimicrobial activities were examined on equal weight basis using the halo zone test. For both bacteria and fungi, the halo zone diameter decreased in the order of p-hydroxyphenyl acrylate (M2)>allyl p-hydroxyphenyl acetate (M1)?p-2-propenoxyphenol (M3). Polymerization of the monomers decreased their antimicrobial activity significantly, but the order

Eun-Soo Park; Woong-Sig Moon; Min-Jin Song; Mal-Nam Kim; Kyoo-Hyun Chung; Jin-San Yoon

2001-01-01

47

Luminescence of benzoic acid polycrystals doped with n-terphenyl and n-quaterphenyl  

SciTech Connect

The luminescence and luminescence excitation spectra of benzoic acid polycrystals, terphenyl, quaterphenyl, and benzoic acid doped with terphenyl and quaterphenyl are studied. Blue shifts of the fluorescence and fluorscence excitation spectra are found. These shifts result from nonplanar entering of polyphenyl molecules into the unit cell of the benzoic acid dimmers around the acid carbonyl groups. In the impurity polycrystals at room temperature, the internal conversion from the triplet level efficiently occurs resulting in the absence of phosphorescence. 12 refs., 4 figs.

Zarochentseva, E.P.; Korotkov, V.I.; Oleinik, Y.P. [St. Petersburg State Univ. (Russian Federation)] [and others

1994-10-01

48

Benzoic acid biosynthesis in cell cultures of Hypericum androsaemum  

Microsoft Academic Search

Biosynthesis of benzoic acid from cinnamic acid has been studied in cell cultures of Hypericum androsaemum L. The mechanism underlying side-chain shortening is CoA-dependent and non-#-oxidative. The enzymes involved are cinnamate:CoA ligase, cinnamoyl-CoA hydratase\\/lyase and benzaldehyde dehydrogenase. Cinnamate:CoA ligase was separated from benzoate:CoA ligase and 4-coumarate:CoA ligase, which belong to xanthone biosynthesis and general phenylpropanoid metabolism, respectively. Cinnamoyl-CoA hydratase\\/lyase catalyzes

Ahmed M. Abd El-Mawla; Ludger Beerhues

2002-01-01

49

Dihydrochalcones and benzoic acid derivatives from Piper dennisii.  

PubMed

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 M) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 M). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data. PMID:22516933

Cabanillas, Billy Joel; Le Lamer, Anne-Ccile; Castillo, Denis; Arevalo, Jorge; Estevez, Yannick; Rojas, Rosario; Valadeau, Cline; Bourdy, Genevive; Sauvain, Michel; Fabre, Nicolas

2012-06-01

50

[Study on THz spectra and vibrational modes of benzoic acid and sodium Benzoate].  

PubMed

Terahertz time-domain spectroscopy was employed to measure the terahertz absorption spectra of benzoic acid and sodium benzoate at room temperature. The origins of the measured features of benzoic acid were summarized based on previous study. Density functional theory was used to compute and analyze the molecular structure and vibrational modes of sodium benzoate in monomer. Based on the obtained results, the authors found that the THz spectral features can be used to distinguish benzoic acid and sodium benzoate totally; the essential reason for the THz spectral difference between benzoic acid and sodium benzoate is that the electrovalent bond of sodium benzoate affects the values of covalent bond lengths and bond angles, as well as the molecular interactions and arrangement in unit cell; the measured features of benzoic acid and sodium benzoate come from the collective vibrations except the peaks located at 107 cm-1 of benzoic acid and 54 cm-1 of sodium benzoate. PMID:23705412

Zheng, Zhuan-Ping; Fan, Wen-Hui; Yan, Hui; Liu, Jia; Xu, Li-Min

2013-03-01

51

Benzoic acid and specific 2-oxo acids activate hepatic efflux of glutamate at OAT2.  

PubMed

The liver is the principal source of glutamate in blood plasma. Recently we have discovered that efflux of glutamate from hepatocytes is catalyzed by the transporter OAT2 (human gene symbol SLC22A7). Organic anion transporter 2 (OAT2) is an integral membrane protein of the sinusoidal membrane domain; it is primarily expressed in liver and much less in kidney, both in rats and humans. Many years ago, Hussinger and coworkers have demonstrated in isolated perfused rat liver that benzoic acid or specific 2-oxo acid analogs of amino acids like e.g. 2-oxo-4-methyl-pentanoate ('2-oxo-leucine') strongly stimulate release of glutamate (up to 7-fold); '2-oxo-valine' and the corresponding amino acids were without effect. The molecular mechanism of efflux stimulation has remained unclear. In the present study, OAT2 from human and rat were heterologously expressed in 293 cells. Addition of 1 mmol/l benzoic acid to the external medium increased OAT2-specific efflux of glutamate up to 20-fold; '2-oxo-leucine' was also effective, but not '2-oxo-valine'. Similar effects were seen for efflux of radiolabeled orotic acid. Expression of OAT2 did not increase uptake of benzoic acid; thus, benzoic acid is no substrate, and trans-stimulation can be excluded. Instead, further experiments suggest that increased efflux of glutamate is caused by direct interaction of benzoic acid and specific 2-oxo acids with OAT2. We propose that stimulators bind to a distinct extracellular site and thereby accelerate relocation of the empty substrate binding site to the intracellular face. Increased glutamate efflux at OAT2 could be the main benefit of benzoate treatment in patients with urea cycle defects. PMID:22981274

Pfennig, Till; Herrmann, Beate; Bauer, Tim; Schmig, Edgar; Grndemann, Dirk

2013-02-01

52

Effects of dietary benzoic acid on urinary pH and nutrient digestibility in lactating sows  

Microsoft Academic Search

Two experiments were conducted to examine the effect of benzoic acid in the diet of lactating sows on urinary pH and nutrient digestibility. In the first experiment, three levels of benzoic acid in the diet were tested (0.5, 1.0, and 2.0%), while in the second experiment only one dietary level of benzoic acid (0.5%) was used. In the second experiment,

H. Kluge; J. Broz; K. Eder

2010-01-01

53

Adsorption of phenol and benzoic acid from dilute aqueous solution onto macroreticular resin  

Microsoft Academic Search

The adsorption of phenol and benzoic acid from dilute aqueous solution onto macroreticular resin was studied by a radiotracer technique for 0.4948-0.0003 mg\\/ml benzoic acid solutions at 25°C and for similar concentrations of phenol at 0°, 25°, and 70°C. Adsorption equilibrium with the Amberlite XAD-8 resin slurry was reached after 44 hr for benzoic acid and after 104 hr for

D. S. Farrier; A. L. Hines; S. W. Wang

1979-01-01

54

Application of a supported iron oxyhydroxide catalyst in oxidation of benzoic acid by hydrogen peroxide  

Microsoft Academic Search

Oxidation of benzoic acid was studied via Fenton-like reaction using an innovative supported ?-FeOOH catalyst. The decomposition kinetics of hydrogen peroxide was investigated first. Oxidation of benzoic acid by hydrogen peroxide was performed to understand the effects of initial pH and hydrogen peroxide dosage. The treatment efficiency of benzoic acid at an initial pH of 3.2 was higher than at

Shanshan Chou; Chihpin Huang

1999-01-01

55

Benzoic acid 2-hydroxylase, a soluble oxygenase from tobacco, catalyzes salicylic acid biosynthesis  

SciTech Connect

Benzoic acid 2-hydroxylase (BA2H) catalyzes the biosynthesis of salicylic acid from benzoic acid. The enzyme has been partially purified and characterized as a soluble protein of 160 kDa. High-efficiency in vivo labeling of salicyclic acid with {sup 18}O{sub 2} suggested that BA2H is an oxygenase that specifically hydroxylates the ortho position of benzoic acid. The enzyme was strongly induced by either tobacco mosaic virus inoculation of benzoic acid infiltration of tobacco leaves and it was inhibited by CO and other inhibitors of cytochrome P450 hydroxylases. The BA2H activity was immunodepleted by antibodies raised against SU2, a soluble cytochrome P450 from Streptomyces griseolus. The anti-SU2 antibodies immunoprecipitated a radiolabeled polypeptide of around 160 kDa from the soluble protein extracts of L-[{sup 35}S]-methionine-fed tobacco leaves. Purified BA2H showed CO-difference spectra with a maximum at 457 nm. These data suggest that BA2H belongs to a novel class of soluble, high molecular weight cytochrome P450 enzymes. 21 refs., 6 figs., 1 tab.

Leon, J.; Shulaev, V.; Yalpani, N. [Rutgers Univ., New Brunswick, NJ (United States)] [and others

1995-10-24

56

Palladium-catalyzed chemoselective decarboxylative ortho acylation of benzoic acids with ?-oxocarboxylic acids.  

PubMed

Palladium-catalyzed chemoselective decarboxylative cross coupling of benzoic acids with ?-oxocarboxylic acids was realized via an arene sp(2) C-H functionalization process. This work represents the first example of transition-metal-catalyzed cross-coupling reactions with two acids acting in different roles. The synthetic utility of this method was confirmed by the synthesis of pitofenone, an antispasmodic used in the combined drug Spasmalgon. PMID:23721458

Miao, Jinmin; Ge, Haibo

2013-06-21

57

Investigation on terahertz vibrational modes of crystalline benzoic acid  

NASA Astrophysics Data System (ADS)

The characteristic absorption features of crystalline benzoic acid in 0.1-4.0 THz have been measured by terahertz time-domain spectroscopy experimentally. Three sharp and low-intensity peaks are observed in the lowest frequency range of 0.1-1.5 THz. In particular, the absorption peak at 0.63 THz is reported for the first time, to the best of our knowledge. Moreover, theoretical simulations have also been performed, and all measured terahertz absorption features are unambiguously assigned. Our calculations clearly show that the first three absorption features arise from translation motions of dimers held together by hydrogen bonds.

Yan, Hui; Fan, Wen-Hui; Zheng, Zhuan-Ping

2012-03-01

58

Infrared Spectroscopy of Hydrogen Bonds in Benzoic Acid Derivatives  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

59

Comparison of Several Extraction Methods for the Isolation of Benzoic Acid Derivatives from Melissa officinalis  

Microsoft Academic Search

Several extraction techniques, such as Soxhlet extraction, solid phase extraction using molecularly imprinted polymer, matrix solid phase dispersion, and supercritical fluid extraction were evaluated for the isolation and purification of phenolic compounds, e.g., benzoic acids from natural samples of Melissa officinalis. The extracts of benzoic acids were analyzed by high performance liquid chromatography (HPLC) in reversed phase modus (C18 column)

Gabriela Karasov; Jozef Lehotay; Ewa K?odzinska; Bogus?aw Buszewski

2006-01-01

60

Electron-impact ionization of benzoic acid, nicotinic acid and their n-butyl esters  

NASA Astrophysics Data System (ADS)

Electron-impact ionization mass spectra, the decay of metastable ions, ionization and appearance energies and bond energies, as dissociation energies, are reported for the title compounds. An ionization energy of 9.47 eV was obtained for benzoic acid, 9.43 eV for benzoic acid n-butyl ester, 9.61 eV for nicotinic acid and 9.97 eV for nicotinic acid n-butyl ester. Molecular ions of both butyl esters show two common main fragmentation pathways: the first process is a McLafferty rearrangement, characterized by the transfer of one H-atom from the aliphatic ester chain, which leads to the ions of either the organic acid or 1-butene. From their appearance energies and known thermodynamic data, gas-phase formation enthalpies () of the parent n-butyl esters are calculated. Values of for benzoic acid n-butyl ester and for nicotinic acid n-butyl ester were obtained. The second process is characterized by the transfer of two H-atoms from the ester chain leading to a protonated form of the corresponding organic acids and C4H7 radicals. Good evidence is provided for the formation of methylallyl radicals. Appearance energies are used to calculate a proton affinity (PA) for benzoic acid. The obtained value of PA = (8.73 0.3) eV, corresponding to a protonation of the carbonyl group, is in close corroboration with published data (PA = 8.51 eV). Activation energies for the intermediate H-transfers were found to be insignificant. This methodic gateway is applied to the system of nicotinic acid and its butyl ester. Adopting the formation of a methylallyl radical, the obtained proton affinity of nicotinic acid, PA = 8.58 eV, is very near to the published data of benzoic acid. An alternative fragmentation mechanism leading to a value of PA [approximate] 9.5 eV (typical for a protonation of the pyridine-nitrogen) is very unlikely. It is concluded that this transfer of two H-atoms from the ester chain is controlled by a charge switching between the carboxylic oxygen atoms which leads to a regiospecific protonation site, in this case to the protonated carbonyl group. This is conform with a B3LYP DFT calculation with a corresponding proton affinity of PA = 8.29 eV.

Opitz, Joachim

2007-08-01

61

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

PubMed

Piper crassinervium, P. aduncum, P. hostmannianum, and P. gaudichaudianum contain the new benzoic acid derivatives crassinervic acid (1), aduncumene (8), hostmaniane (18), and gaudichaudianic acid (20), respectively, as major secondary metabolites. Additionally, 19 known compounds such as benzoic acids, chromenes, and flavonoids were isolated and identified. The antifungal activity of these compounds was evaluated by bioautographic TLC assay against Cladosporium cladosporioides and C. sphaerospermum. PMID:15568762

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

2004-11-01

62

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Benzoic acid, 3,3â²-methyl-enebis...Substances § 721.1725 Benzoic acid, 3,3-methyl-enebis...substance, referred to by its CAS Number and chemical name, is subject...section: 61386-02-5, Benzoic acid, 3,3-methylenebis...

2013-07-01

63

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

Code of Federal Regulations, 2010 CFR

...2012-07-01 2012-07-01 false Benzoic acid, 3,3â²-methyl-enebis [6...Specific Chemical Substances § 721.1725 Benzoic acid, 3,3-methyl-enebis [6...2) of this section: 61386-02-5, Benzoic acid, 3,3-methylenebis [6...

2012-07-01

64

Estimating the acidity of singly and multiply substituted benzoic acids via electrostatic potential at the nucleus  

NASA Astrophysics Data System (ADS)

We established two good linear relationships between p Ka and acidic atom's electrostatic potential (MEP) in the gas phase by DFT methods at B3LYP/6-31+G( d, p) level of theory. We studied 13 experimentally well-characterized singly substituted benzoic acids to determine the best level of theory. A good linear relationship between MEP and the experimental p Ka data has been revealed (standard deviation (STD) = 0.081, R2 = 0.937 for model 1; STD = 0.081, R2 = 0.934 for model 2), better than the computational results in the literatures. Our models also showed that it is reliable to estimate the p Ka values of multiply substituted benzoic acids.

Zhong, Ai-Guo; Jiang, Hua-Jiang; Liang, Hua-Ding

2011-08-01

65

Molecular design and synthesis of functional photothermopolymers from hydroxyl benzoic acids  

NASA Astrophysics Data System (ADS)

The most applicable hydroxyl benzoic acid monomers were optimized to synthesize the thermolysis-decarboxylation polymers according to the relative results of TG analysis of hydroxyl benzoic acids, their 13C-NMR spectra analyses and their quantum chemistry calculation with AB-INITIO method. On the basis of the empirical rule -- M/A value rule, while phenols with high M/A value and hydroxyl benzoic acids were both cocondensed with formaldehyde at proper ratio, the novolak resin with carboxyl groups used as a thermal imaging material could be obtained. In the presence of an acid catalyst, such as oxalic acid, a hydroxyl benzoic acid could be additionally polymerized with divinyl benzene (DVB) to synthesize another kind of polymer with not only carboxyl groups but also phenolic hydroxyl groups. The thermal imaging mechanisms of these polymers with carboxyl groups were discussed in the paper.

Tong, Xiao; Gu, Jiangnan; Wang, Liyuan; Zou, Yingquan; Yu, Shangxian

2000-06-01

66

Synergistic extraction of europium(III) with benzoic acid and thenoyltrifluoroacetone  

SciTech Connect

The solvent extraction of europium(III) into solutions of thenoyltrifluoroacetone and benzoic acid in cyclohexane, carbon tetrachloride, benzene, chloroform, pentachloroethane, and tetrachloroethane has been measured at 25/sup 0/ C. It has been found that the extracted species involve two types of adducts, EuA/sub 3/HB and EuA/sub 3/ . 2HB where A denotes the TTA anion and HB the benzoic acid monomer. The magnitude of the adduct formation constants in different solvents has been correlated with the dimerization constants of benzoic acid in the solvents. 2 figures, 2 tables.

Hasegawa, Y.; Nakano, T.

1983-01-01

67

Selective adsorption of benzoic acid species on patterned OH/Si(100) surface  

SciTech Connect

It has recently been observed that benzoic acid strongly reacts with OH group on the silicon surface. Here, by defining the area in which OH group is adsorbed on the Si surface, the selective adsorption of benzoic acid species was attempted. The patterned OH/Si surface was prepared by irradiating the zeroth order beam from the bending magnet of the synchrotron facility through the gold mesh placed in front of the OH/Si sample. For discerning the selectively adsorbed molecule by x-ray photoelectron emission microscopy (X-PEEM) at N k edge, 4-nitrobenzoic acid was utilized instead of benzoic acid. Near edge x-ray absorption fine structure spectra at carbon and oxygen k edges were in good accord with the previous results obtained from the benzoic acid system. The X-PEEM images around N k edge clearly showed that the molecules adsorb only on the area in which OH groups remain.

Ihm, Kyuwook; Han, Jin Hee; Kim, Bongsoo; Chung, Sukmin; Hwang, Chan-Cuk; Kang, Tai-Hee; Kim, Ki-Jeong; Jung, Yu Jin; An, Ki-Seok [Department of Physics, POSTECH, Pohang, Kyungbuk 790-784 (Korea, Republic of) and Beamline Research Division, Pohang Accelerator Laboratory (PAL), Pohang, Kyungbuk 790-984 (Korea, Republic of); Beamline Research Division, Pohang Accelerator Laboratory (PAL), Pohang, Kyungbuk 790-784 (Korea, Republic of); Division of Molecular and Life Sciences, Department of Chemistry, Center for Integrated Molecular Systems, POSTECH, Pohang, Kyungbuk 790-784 (Korea, Republic of); Thin Film Materials Laboratory, Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon 305-600 (Korea, Republic of)

2006-08-15

68

New prenylated benzoic acid and other constituents from almond hulls (Prunus amygdalus Batsch).  

PubMed

One new prenylated benzoic acid derivative, 3-prenyl-4-O-beta-D-glucopyranosyloxy-4-hydroxylbenzoic acid, and three known constituents, catechin, protocatechuic acid, and ursolic acid, have been isolated from the hulls of almond (Prunus amygdalus). Complete assignments of the proton and carbon chemical shifts for the new prenylated benzoic acid derivative were accomplished on the basis of high-resolution 1D and 2D nuclear magnetic resonance data. All of these compounds except ursolic acid are being reported from almond hulls (P. amygdalus) for the first time. PMID:11804537

Sang, Shengmin; Lapsley, Karen; Rosen, Robert T; Ho, Chi-Tang

2002-01-30

69

Benzoic acid transformation via conjugation with peptides and final fate of conjugates in higher plants.  

PubMed

Transformation of [1(14)C]- and [7(14)C] benzoic acids in sterile seedlings of maize (Zea mays) and pea (Pisum sativum) was studied. The tested labeled compounds were supplied in plants through roots as water solutions. The larger part of the assimilated benzoic acid forms conjugates with low-molecular-weight plant peptides. As a result of hydrolytic cleavage of the conjugation products, initial labeled benzoic acid molecules and unlabeled amino acids are released. It is supposed that conjugation takes place between the benzoic acid carboxyl group and the peptide functional groups. The amino acid composition of the conjugate peptides was determined. After removal of the plants from the labeled benzoic-acids-containing medium, the amount of conjugation products gradually decreases and the process is accompanied by the emission of labeled carbon dioxide, indicating that the conjugation products are degraded and that their radioactive component carbon atoms are then oxidized to carbon dioxide. Parallel to the conjugation reaction, a smaller part of the benzoic acid that entered the plant is transformed via oxidation, as a result of which an aromatic ring is cleaved and the resulting aliphatic fragment is incorporated into regular cell metabolism. The smallest part of the assimilated benzoic acid radiolabel is incorporated into a cell biopolymer fraction. Benzoic acid, of which the radioactive label is detected in the plant subcellular organelles and finally deposited in the vacuoles, affects the cell ultrastructural organization and the activities of the main metabolic enzymes. Intensification of catabolic processes takes place, indicating an energy demand needed for xenobiotic detoxification. PMID:15964071

Chrikishvili, D; Sadunishvili, T; Zaalishvili, G

2006-07-01

70

The conversion of L-phenylalanine into benzoic acid on the thylakoid membrane of higher plants.  

PubMed

The conversion of L-phenylalanine into benzoic acid and other aromatic carboxylic acids was investigated in Nasturtium officinale (watercress), Astilbe chinensis, and Hydrangea macrophylla in vivo and in vitro. Comparative feeding experiments with radioactively labelled L-phenylalanine and cinnamic acid administered to intact leaf discs of A. chinensis indicated a rapid formation of benzoic acid from L-phenylalanine, whereas cinnamic acid was a poor precursor. Using a pulse-chase labelling technique followed by a fractionation of the tissue into subcellular components, chloroplasts could be identified as the predominant, if not exclusive, site of benzoic acid formation in A. chinensis. Experiments in vitro with chloroplasts and thylalkoids of N. officinale, H. macrophylla, and A. chinensis demonstrate the capacity of thylakoid membranes to catalyze the degradation of L-phenylalanine to benzoic acid. The results obtained upon stimultaneous incubation with [4'-3H]L-phenylalanine and [3-14C]cinnamic acid lead to the hypothesis that the reaction of L-phenylalanine to benzoic acid proceeds via a cinnamic acid pool which is different from that of soluble cinnamic acid. PMID:1158329

Lffelhardt, W; Kindl, H

1975-05-01

71

Adsorption of benzoic acid onto high specific area activated carbon cloth  

Microsoft Academic Search

The adsorption of benzoic acid from aqueous solution onto high area carbon cloth at different pH values has been studied. Over a period of 125 min the adsorption process was found to follow a first-order kinetics and the rate constants were determined for the adsorption of benzoic acid at pH 2.0, 3.7, 5.3, 9.1, and 11.0. The extents of adsorption

Erol Ayranci; Numan Hoda; Edip Bayram

2005-01-01

72

Antimicrobial screening and quantitative determination of benzoic acid derivative of Gomphrena celosioides by TLC-densitometry.  

PubMed

The antimicrobial activity of ethanolic extract and pure compounds of Gomphrena celosioides have been screened by Kirby-Bauer method. Quantitative determination of 4-hydroxy-3-methoxy-benzoic acid in stems, leaves, flowers and roots was established by TLC-densitometry. Results showed significant activity against Staphylococcus aureus and Salmonella typhi. There were no significant differences in the determined benzoic acid derivative. PMID:15516759

de Moura, Rute Mendona Xavier; Pereira, Paulo Srgio; Janurio, Ana Helena; Frana, Suzelei de Castro; Dias, Diones Aparecida

2004-11-01

73

Impact of several water-miscible organic solvents on sorption of benzoic acid by soil  

Microsoft Academic Search

Sorption of benzoic acid by a surface soil was measured from several binary mixtures of water and various organic cosolvents spanning a wide range in solvent properties. For all solvents investigated, the addition to an aqueous solution resulted in an increase in solubility and an alkaline shift in the conditional ionization constant (pK{sub a}{sup c}) of benzoic acid. Sorption data

Linda S. Lee; P. Suresh C. Rao

1996-01-01

74

Synthesis and characterisation of 3- and 4-(pentafluorosulfanyl)benzoic acid derivatives  

Microsoft Academic Search

The high yield synthesis of 3- and 4-(pentafluorosulfanyl)benzoic acid derivatives is described starting from the NO2-derivatives, which are reduced to the corresponding anilines. Then the NH2 group is converted to bromide and subsequently to the HCO moiety. The benzaldeydes are then oxidised to the corresponding benzoic acids. The X-ray structure of 3SF5C6H4COOH is also reported.

C. Zarantonello; A. Guerrato; E. Ugel; R. Bertani; F. Benetollo; R. Milani; A. Venzo; A. Zaggia

2007-01-01

75

Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid and sodium lauryl sulfate  

SciTech Connect

Acid mine drainage is formed by the weathering or oxidation of pyritic material exposed during coal mining. The rate of pyritic material oxidation can be greatly accelerated by certain acidophilic bacteria such as Thiobacillus ferrooxidans which catalyse the oxidation of ferrous to ferric iron. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage micro-organisms. Sodium lauryl sulphate (SLS), an anionic surfactant has proved effective in this respect. Benzoic acid, sorbic acid and SLS at low concentrations, each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of T. ferrooxidans. The rate of chemical oxidation of ferrous iron in low pH, sterile, batch reactors was not substantially affected at the tested concentrations of any of the compounds.

Onysko, S.J.

1984-07-01

76

Effects of benzoic and cinnamic acids on growth, mineral composition, and chlorophyll content of soybean  

Microsoft Academic Search

Organic acids are major water-soluble allelochemicals found in soil infested with quackgrass and are involved in several processes that are important in plant growth and development. This study was carried out to gain more information on the effects of benzoic acid (BEN) andtrans-cinnamic acid (CIN) on growth, mineral composition, and chlorophyll content of soybean [Glycine max (L.) Merr. cv. Maple

R. Baziramakenga; R. R. Simard; G. D. Leroux

1994-01-01

77

Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid, and sodium lauryl sulfate  

SciTech Connect

Thiobacillus ferrooxidans promote indirect oxidation of pyrite through the catalysis of the oxidation of ferrous iron to ferric iron, which is an effective oxidant of pyrite. These bacteria also may catalyze direct oxidation of pyrite by oxygen. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous iron to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage microorganisms. In this study, 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.

Onysko, S.J.; Kleinmann, R.L.P.; Erickson, P.M.

1984-07-01

78

Energy transfer from benzoic acid to lanthanide ions in benzoic acid-functionalized lanthanide-doped CaF 2 nanoparticles  

NASA Astrophysics Data System (ADS)

The preparation of benzoic acid-functionalized CaF 2:Ln 3+ (Ln = Eu or Tb) nanoparticles and their sensitized luminescence are described in this report. First, to achieve sufficient proof for energy transfer from benzoic acid (BA) to lanthanide ions doped in nanoparticles, we employ Eu 3+ as the microscopic probe and investigate the luminescent spectra of benzoic acid-functionalized CaF 2:Eu 3+ (BA-CaF 2:Eu 3+) nanoparticles. Next, to further reveal the difference between sensitized luminescence and common luminescence for Eu 3+ doped in CaF 2 nanoparticles, we study the emission spectra of BA-CaF 2:Eu 3+ nanoparticles excited at 286 nm and 397 nm, respectively. Finally, we analyze and compare the luminescent spectra of BA-CaF 2:Tb 3+ and CaF 2:Ce 3+, Tb 3+ nanoparticles in detail. Our results indicate that both Eu 3+ and Tb 3+ doped in CaF 2 nanoparticles can be efficiently sensitized through benzoic acid.

Wang, Jianshe; Wang, Zongwu; Li, Xia; Wang, Si; Mao, Huadan; Li, Zhongjun

2011-06-01

79

The thermochemical characteristics of solution of phenol and benzoic acid in water-dimethylsulfoxide and water-acetonitrile mixtures  

NASA Astrophysics Data System (ADS)

The solution of phenol and benzoic acid in water-dimethylsulfoxide (DMSO) and water-acetonitrile (AN) mixtures was studied. As distinct from benzoic acid, the thermodynamic characteristics of solution of phenol sharply change at concentrations corresponding to a change in the character of cluster formation in water-DMSO and water-AN mixtures. Differences in the solvation of phenol and benzoic acid are explained by different mechanisms of the interaction of the solutes with clusters existing in binary mixtures.

Zakharov, A. G.; Voronova, M. I.; Batov, D. V.; Smirnova, K. V.

2011-03-01

80

Benzoic acid-degrading bacteria from the intestinal tract of Macrotermes michaelseni Sjstedt.  

PubMed

The intestinal tracts of termites host a wide variety of microbial symbionts, which have been implicated in degradative processes. In this study, a fungus-cultivating termite, Macrotermes michaelseni was found to harbor 2.2 x 10(6) bacterial cells per ml of gut homogenates capable of degrading benzoic acid. Two benzoic acid degrading bacteria were isolated from the highest dilution of gut homogenates in oxic media with benzoic acid as the sole carbon source. Isolate CBC was related to Stenotrophomonas maltophila LMG 958(T), Xanthomonas campestris DSM 3586(T) and Stenotrophomonas acidaminophila DSM 13117(T) with a sequence similarity of 98.3%, 94.7% and 94.2%, respectively. Isolate CBW was related to Enterobacter aerogenes JCM 1235(T) and Raoultella ornithinolytica ATCC 31898(T) with sequence similarity of 98.4% and 97.8%, respectively. In addition to growing on benzoic acid (up to 9 mM) aerobically, isolate CBW also degraded benzoic acid under anoxic conditions with nitrate as electron acceptor. Isolate CBC did not degrade bezoic acid with nitrate but could degraded resorcinol under oxic conditions. PMID:17304624

Kamanda Ngugi, David; Khamis Tsanuo, Muniru; Iddi Boga, Hamadi

2007-02-01

81

Effect of chlorophenoxyacetic acid herbicides on glycine conjugation of benzoic acid.  

PubMed

1. 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) (0.1-0.5 mmol/kg i.p.) delayed the disappearance of injected benzoate from blood and diminished the urinary excretion of the formed benzoylglycine, but elevated the blood levels of benzoylglycine in rat, suggesting that these herbicides interfere with both the formation and the renal transport of benzoylglycine. 2. Inhibition of the renal excretion of benzoylglycine by 2,4-D or 2,4,5-T (0.5 mmol/kg i.p.) was directly demonstrated in rat injected with benzoylglycine. 3. Inhibition of benzoylglycine formation from benzoic acid by 2,4-D or 2,4,5-T (0.5 mmol/kg i.p.) was directly demonstrated in renal pedicles-ligated rats injected with benzoate. 4. Neither 2,4-D nor 2,4,5-T influenced the hepatic concentrations of ATP, coenzyme A (CoA) or glycine; therefore, it is unlikely that they inhibit glycine conjugation of benzoic acid by diminishing the availability of co-substrates. 5. Although the chlorophenoxyacetic acids did not appear to be a substrate for the mitochondrial acyl-CoA synthetases, both 2,4-D and 2,4,5-T diminished the activity of benzoyl-CoA synthetase (but not that of benzoyl-CoA:glycine N-acyltransferase) in solubilized hepatic mitochondria. These findings suggest that 2,4-D and 2,4,5-T impair benzoylglycine formation in rat by inhibiting benzoyl-CoA synthetase. PMID:10426554

Gregus, Z; Halszi, E; Klaassen, C D

1999-06-01

82

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

ERIC Educational Resources Information Center

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

Treadwell, Edward M.; Lin, Tung-Yin

2008-01-01

83

Electrochemical oxidation of benzoic acid at boron-doped diamond electrodes  

Microsoft Academic Search

The electrochemical oxidation of benzoic acid (BA) has been studied on boron-doped diamond electrodes on acid medium by cyclic voltammetry and bulk electrolysis. The results showed that in the potential region where the supporting electrolyte is stable, reactions occur, resulting in the loss of activity due to electrode fouling. Electrolysis at high anodic potentials in the region of electrolyte decomposition

F Montilla; P. A Michaud; E Moralln; J. L Vzquez; Ch Comninellis

2002-01-01

84

Effects of benzoic and cinnamic acids on membrane permeability of soybean roots  

Microsoft Academic Search

Benzoic (BEN) and cinnamic (CIN) acids are commonly found in soils and are considered as strong allelochemicals. Published information suggest that BEN and CIN and other phenolic acids decrease plant growth in part by suppressing nutrient absorption. However, studies on the mechanism of action were not conclusive. We examined the effects of BEN and CIN on the cell plasma membrane

R. Baziramakenga; G. D. Leroux; R. R. Simard

1995-01-01

85

Formation of phenol under conditions of the reaction of oxidative carbonylation of benzene to benzoic acid  

SciTech Connect

This paper describes conditions for the oxidation of benzene to phenol. It is shown that a reaction mixture of water, carbon monoxide, and oxygen are essential to the oxidation. The oxidation is a side reaction found to occur during the oxidative carbonylation of benzene to benzoic acid in a medium of trifluoroacetic acid.

Kalinovsky, I.O.; Leshcheva, A.N.; Pogorelov, V.V.; Gelbshtein, A.I.

1993-12-31

86

Liquid-phase reactions induced by gaseous plasma. Decomposition of benzoic acids in aqueous solution  

Microsoft Academic Search

The liquid-phase organic reactions induced by a gaseous plasma, which was generated in a localized zone between an electrolytic solution and an anode by means of contact glow discharge electrolysis (CGDE), were investigated. Benzoic acids dissolved in a neutral phosphate buffer solution were efficiently oxidized and eventually decomposed to inorganic carbon. As the intermediate products, oxalic, formic and malonic acids

M. Tezuka; M. Iwasaki

1999-01-01

87

Variability of olfactory receptor neuron responses of female silkmoths ( Bombyx mori L.) to benzoic acid and ()-linalool  

Microsoft Academic Search

Of the two sensory neurons present in each sensillum trichodeum on antennae of female silk-moths, Bombyx mori, one was activated by stimulation with benzoic acid (benzoic acid cell), the other with ()-linalool (terpene cell). Using single-cell recordings we studied the temporal characteristics of the nerve impulse response of both cell types. The time course of the impulse response was shown

Thomas Heinbockel; Karl-Ernst Kaissling

1996-01-01

88

Deuteration of pentacene in benzoic acid: Monitoring the reaction kinetics via low-temperature optical spectroscopy  

SciTech Connect

In the deuteration of pentacene in benzoic acid, this reaction is monitored via low-temperature optical spectroscopy to observe the proton-deuterium rate of exchange between the solvent and solute molecules. Of the 14 pentacene protons, 6 have an exchange rate 2 orders of magnitude greater than the remaining 8. 20 refs., 3 figs.

Corval, A.; Casalegno, R.; Astilean, S.; Trommsdorff, H.P. [Universite Joseph Fourier, Grenoble (France)

1992-06-25

89

Benzoic acid degradation by small, pilot-scale artificial wetlands filter (AWF) systems  

Microsoft Academic Search

Subsurface-flow constructed wetlands (SF) or artificial wetlands filter (AWF) systems were examined for potential use in the removal from various waste streams of complex halogenated and nonhalogenated organic compounds as represented by benzoic acid (BA). Three small, pilot-scale AWF systems with differing reactor configurations including two planted reactors (Scirpus validus Valn) and an unplanted control, were run on a continuous

Walter H. Zachritz; Leon L. Lundie; Harry Wang

1996-01-01

90

Antihepatotoxic activity of p-methoxy benzoic acid from Capparis spinosa  

Microsoft Academic Search

p-Methoxy benzoic acid isolated from the methanolic soluble fraction of the aqueous extract of Capparis spinosa L. (Capparidaceae) was found to possess significant antihepatotoxic activity against carbontetrachloride and paracetamol induced hepatotoxicity in vivo and thioacetamide and galactosamine induced hepatotoxicity in isolated rat hepatocytes, using in vitro technique. The compound was characterized through physicochemical and spectral studies. Isolation, identification and antihepatotoxic

Chhaya Gadgoli; S. H Mishra

1999-01-01

91

Competitive adsorption of benzoic acid and p-nitrophenol onto activated carbon: isotherm and breakthrough curves  

Microsoft Academic Search

Three series of batch tests at 25C were performed to determine the benzoic acid and p-nitrophenol (PNP) binary adsorption isotherms onto GAC in the aqueous solutions and the experimental data were fitted to the extended Langmuir isotherm model successfully. The experimental data and the isotherm model parameters showed that the GAC used in this study had a higher affinity to

Jia-Ming Chern; Yi-Wen Chien

2003-01-01

92

40 CFR 721.10020 - Benzoic acid, 5-amino-2-chloro-, 1,1-dimethyl-2-oxo-2-(2-propenyloxy) ethyl ester.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Benzoic acid, 5-amino-2-chloro-, 1,1-dimethyl-2-oxo-2...Substances § 721.10020 Benzoic acid, 5-amino-2-chloro-, 1,1-dimethyl-2-oxo-2...substance identified as benzoic acid, 5-amino-2-chloro-,...

2013-07-01

93

5Nitro2-(3-Phenylpropylamino)benzoic Acid Is a GPR35 Agonist  

Microsoft Academic Search

GPR35 is a Gi\\/o- and G16-coupled receptor abundantly expressed in gastrointestinal tissues and immune cells. Kynurenic acid (a tryptophan metabolite and ionotropic glutamate receptor antagonist) and zaprinast (a phosphodies- terase inhibitor) are GPR35 agonists. Here, we show that the chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) is also a GPR35 agonist. NPPB activates the GPR35-Gi\\/o and GPR35-G16 pathways in human

Yasuhito Taniguchi; Hiroko Tonai-Kachi; Katsuhiro Shinjo

2008-01-01

94

Catalytic hydroxylation of benzoic acid by hydrogen peroxide  

SciTech Connect

An effective catalytic system based on Fe(III) and surfactants is proposed for the hydroxylation of benozic acid by hydrogen peroxide in an aqueous medium at a temperature of 30-80{degrees}C. 8 refs., 1 tab.

Pulippurasseril, C.R.; Filippova, T.Yu.; Dedov, A.G. [M.V. Lomonosov Moscow State Univ. (Russian Federation)

1992-12-31

95

Structure-activity relationship study on benzoic acid part of diphenylamine-based retinoids.  

PubMed

Based on structure-activity relationship studies of the benzoic acid part of diphenylamine-based retinoids, the potent RXR agonist 4 was derivatized to obtain retinoid agonists, synergists, and an antagonist. Cinnamic acid derivatives 5 and phenylpropionic acid derivatives 6 showed retinoid agonistic and synergistic activities, respectively. The difference of the activities is considered to be due to differences in the flexibility of the carboxylic acid-containing substituent on the diphenylamine skeleton. Compound 7, bearing a methyl group at the meta position to the carboxyl group, was an antagonist, dose-dependently inhibiting HL-60 cell differentiation induced by 3.3 10(-10)M Am80. PMID:23217961

Ohta, Kiminori; Kawachi, Emiko; Shudo, Koichi; Kagechika, Hiroyuki

2013-01-01

96

Simultaneous determination of gallic acid, albiflorin, paeoniflorin, ferulic acid and benzoic acid in SiWu decoction by high-performance liquid chromatography DAD method  

Microsoft Academic Search

A high-performance liquid chromatographic method was applied to the determination of gallic acid, albiflorin, paeoniflorin, ferulic acid and benzoic acid in SiWu decoction and other 13 combinations of the formula. These five compounds were analyzed simultaneously with a Zorbox SB C-18 column by gradient elution using 0.01% (v\\/v) phosphoric acidacetonitrile as the mobile phase. The flow rate was 1mlmin?1, and

Yu-Xin Sheng; Lie Li; Qiao Wang; Hong-Zhu Guo; De-An Guo

2005-01-01

97

Evaluation of benzoic acid derivatives as sirtuin inhibitors.  

PubMed

Employing a genetically modified yeast strain as a screening tool, 4-dimethylaminobenzoic acid (5) was isolated from the marine sediment-derived Streptomyces sp. CP27-53 as a weak yeast sirtuin (Sir2p) inhibitor. Using this compound as a scaffold, a series of disubstituted benzene derivatives were evaluated to elucidate the structure activity relationships for Sir2p inhibition. The results suggested that 4-alkyl or 4-alkylaminobenzoic acid is the key structure motif for Sir2p inhibitory activity. The most potent Sir2p inhibitor, 4-tert-butylbenzoic acid (20), among the tested compounds in this study turned out to be a weak but selective SIRT1 inhibitor. The calculated binding free energies between the selected compounds and the catalytic domain of SIRT1 were well correlated to their measured SIRT1 inhibitory activities. PMID:24269123

Chen, Yi-Pei; Catbagan, Chad C; Bowler, Jeannette T; Gokey, Trevor; Goodwin, Natalie D M; Guliaev, Anton B; Wu, Weiming; Amagata, Taro

2014-01-01

98

Antihyperlipidemic action of a newly synthesized benzoic acid derivative, S-2E  

Microsoft Academic Search

A newly synthesized benzoic acid derivative, (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl]methoxybenzoic acid (S-2E), has the capacity to inhibit the biosynthesis of both sterol and fatty acids. Here, we report the mechanism by which S-2E lowers blood cholesterol and triglyceride levels. In the liver, S-2E was converted into its active metabolite, S-2E-CoA. S-2E-CoA noncompetitively inhibited the enzymatic activities of both 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase and

Koichi Ohmori; Haruo Yamada; Akio Yasuda; Akira Yamamoto; Naosuke Matsuura; Mamoru Kiniwa

2003-01-01

99

A chromene and prenylated benzoic acid from Piper aduncum.  

PubMed

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. PMID:10423861

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

1999-08-01

100

A chromene and prenylated benzoic acid from Piper aduncum  

Microsoft Academic Search

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 Piperaduncum, 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 ESMS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae.

Debora Cristina Baldoqui; Massuo Jorge Kato; Alberto Jos Cavalheiro; Vanderlan da Silva Bolzani; Maria Claudia M. Young; Maysa Furlan

1999-01-01

101

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

Microsoft Academic Search

A reversed-phased HPLC method that allows the separation and simultaneous determination of the preservatives benzoic (BA) and sorbic acids (SA), methyl- (MP) and propylparabens (PP) is described. The separations were effected by using an initial mobile phase of methanolacetate buffer (pH 4.4) (35:65) to elute BA, SA and MP and changing the mobile phase composition to methanolacetate buffer (pH 4.4)

Bahruddin Saad; Muhammad Idiris Saleh; Kamarudzaman Ahmad; Mohd. Khairuddin Mohd. Talib

2005-01-01

102

Influence of alternative electron acceptors on the anaerobic biodegradability of chlorinated phenols and benzoic acids  

SciTech Connect

Nitrate, sulfate, and carbonate were used as electron acceptors to examine the anaerobic biodegradability of chlorinated aromatic compounds in estuarine and freshwater sediments. The respective denitrifying, sulfidogenic, and methanogenic enrichment cultures were established on each of the monochlorinated phenol and monochlorinated benzoic acid isomers, using sediment from the upper (freshwater) and lower (estuarine) Hudson River and the East River (estuarine) as source materials. (Copyright (c) 1993 American Society for Microbiology.)

Haeggblom, M.M.; Rivera, M.D.; Young, L.Y.

1993-01-01

103

Benzoic acid metabolism reflects hepatic mitochondrial function in rats with long-term extrahepatic cholestasis  

Microsoft Academic Search

Benzoic acid metabolism, which is primarily a function of liver mitochondria, depending on the concentration of adenosine triphosphate (ATP), coenzyme A (CoA), and glycine in the mitochondrial matrix, was investigated in both rats with long-term cholestasis caused by bile duct ligation (BDL) and sham-operated control rats. In isolated liver mitochondria, hippurate production from benzoate in the presence of saturating glycine

L Krhenbhl; J Reichen; C Talos; S Krhenbhl

1997-01-01

104

Inhibitive detection of benzoic acid using a novel phenols biosensor based on polyanilinepolyacrylonitrile composite matrix  

Microsoft Academic Search

A novel sensitive and stable phenols amperometric biosensor, based on polyanilinepolyacrylonitrile composite matrix, was applied for determination of benzoic acid. The electrochemical biosensor functioning was based on the inhibition effect of benzoic acid on the biocatalytic activity of the polyphenol oxidase (PPO) to its substrate (catechol) in 0.1M phosphate buffer solution (pH 6.5). A potential value of ?50mV versus SCE,

Dan Shan; Qiaofang Shi; Daobin Zhu; Huaiguo Xue

2007-01-01

105

ESR study of the photochemistry of benzoic acid derivatives  

SciTech Connect

Electron spin resonance (ESR) has been used to study radical intermediates in the photochemistry of a number of aromatic carboxylic acids, esters, anhydrides, amides, imides, and nitriles. Continuous photolysis was used to produce the radicals in either aqueous or alcoholic media. The triplet states of the compounds undergo two reactions in the presence of a hydrogen donor such as 2-propanol. A hydrogen atom is transferred to certain carbon atoms of the aromatic ring forming cyclohexadienyl radicals. In most cases, addition occurs at or opposite the carboxyl (or cyano) group. The pattern of addition is attributed to the higher spin density in the triplet at those positions. This pattern also correlates with the positions of higher hyperfine splitting in the corresponding anion radicals. In a parallel reaction, a hydrogen atom is also transferred to an oxygen of the carboxyl group (for acids, anhydrides, and esters) to form the one-electron-reduction product. The cyclohexadienyl radicals are not formed by protonation on a carbon of an anion radical. The ESR spectra of most of the cyclohexadienyl radicals are highly polarized to the extent that the low-field lines appear in emission. This effect is believed to be normal chemically induced dynamic spin polarization (CIDEP) as a result of cross reactions with the other radicals present. 46 refs., 7 figs., 10 tabs.

Jeevarajan, A.S.; Fessenden, R.W. (Univ. of Notre Dame, IN (United States))

1992-12-16

106

Thermal and dielectric studies of self-assembly systems formed by hydroquinone and alkyloxy benzoic acids  

NASA Astrophysics Data System (ADS)

Self-assembly systems formed by hydroquinone and alkyloxy benzoic acids are isolated and characterized. Hydroquinone formed double hydrogen bonds with p- n-alkyloxy benzoic acids. Various hydrogen bonded complexes have been synthesized with hydroquinone and pentyloxy to dodecyloxy benzoic acid, respectively. FTIR studies confirm the hydrogen bond formation in the complex. Polarizing Optical Microscopic (POM) studies revealed the textural information while the transition and enthalpy values are experimentally deduced from Differential Scanning Calorimetry (DSC) studies. Phase diagram has been constructed from the POM and DSC data. The members of the present homologous complexes are characterized by POM, DSC, optical tilt angle and dielectric studies. Odd-even effect has been evinced in enthalpy values and transition temperatures corresponding to the isotropic to nematic phase transition. Optical tilt angle in Smectic C phase data has been fitted to a power law and it has been observed that the temperature variation of the tilt angle follows Mean Field theory prediction. Results of Fourier Transform Infrared Spectra (FTIR), POM, DSC, tilt angle and dielectric studies are discussed.

Pongali Sathya Prabu, N.; Vijayakumar, V. N.; Madhu Mohan, M. L. N.

2011-03-01

107

Anaerobic decomposition of benzoic acid during methane fermentation: Specific activity of fatty acid intermediates and postion of radioactive label  

SciTech Connect

A study of the pathway of anaerobic decomposition of benzoic acid by a mixed methanogenic culture of bacteria was conducted. Specific activities of the possible fatty acid intermediates cyclohexanecarboxylic acid, propanoic acid, and acetic acid were determined. In the case of propanoic acid, the position of the radioactive label was also determined by isotropic trapping and Phares-Schmidt degradation of the intermediate. The specific activities of cyclohexanecarboxylic acid and propanoic acid are the same as the benzoate substrate fed to the mixed methanogenic cultures. These fatty acids must be direct breakdown products from the aromatic ring. When (4{minus}{sup 14}C) benzoate is the substrate, the propanoic acid produced is labeled exclusively in the carboxyl position. This supports the pathway proposed by Keith et al. (1978), but would be unlikely for the pathway proposed by Evans (1977). The specific activity of the acetic acid isolated from a culture fed (4{minus}{sup 14}C) benzoate is 42% of the specific activity of the substrate. This is possible only if the methylmalonyl-CoA pathway for the conversion of propanoate to acetate is not being utilized. The amount of various intermediates found indicates that at least three syntrophically linked organisms are present in the mixed methanogenic culture. One is responsible for the production of cyclohexanecarboxylic acid, one for the production of acetate from propanoate, and one for the production of methane.

Bridges, R.L.

1990-01-01

108

Alkoxy-benzoic acids: Some lacking structures and rationalization of the molecular features governing their crystalline architectures  

NASA Astrophysics Data System (ADS)

The crystalline structure of four alkoxy-substituted benzoic acids, namely 3-(methoxy)benzoic acid (I), (with two independent molecules in the asymmetric unit); 3,4-di(ethoxy)benzoic acid (II), 3,5-di(ethoxy)benzoic acid (III) and 3,4,5-tri(ethoxy)benzoic acid (IV) are presented, and the details of their packing arrangements discussed. In all cases the synthon is a H-bonded head-to-head dimer. C-H⋯? interactions involving C atoms at the 4-positions of neighbouring molecules organize the dimeric synthons in a perpendicular orientation in the case of I. These interactions being blocked for II, Van der Waals interchain interactions organise synthons therein in parallel orientation. In the case of III, although C-H⋯? interactions at the 4-positions are possible in principle, interchain interactions prevail, giving rise to a parallel arrangement of linear strands. Finally, compound IV with all three 3,4,5 substituted sites reduces its interaction scheme to stacking contacts, and the columns thus formed are essentially non interacting. An attempt to rationalize the molecular factors influencing the structures of the whole set of 3-, 4- and/or 5-methoxy- and ethoxy-substituted benzoic acids reported so far in the literature is performed.

Raffo, Pablo A.; Rossi, Leonardo; Albors, Pablo; Baggio, Ricardo F.; Cukiernik, Fabio D.

2014-07-01

109

Solid-Liquid Equilibria of Benzoic Acid Derivatives in 1Octanol * * Supported by the National Natural Science Foundation of China (No.20676101) and the Natural Science Foundation of Tianjin University of Science & Technology (No.20050207)  

Microsoft Academic Search

The solid-liquid equilibrium of benzoic acid derivatives in 1-octanol was first determined in this article. Using a laser monitoring observation technique, the solubility data of 0-amino-benzoic acid, p-amino-benzoic acid, 0-chloro-benzoic acid, and m-nitro-benzoic acid in 1-octanol were measured by the polythermal method in the temperature range of 2050C. The experimental data were regressed with the Wilson equation and the ?H

Qingzhu JIA; Peisheng MA; Shaona MA; Chang WANG

2007-01-01

110

Dicarboxylic acids, ketocarboxylic acids, ?-dicarbonyls, fatty acids, and benzoic acid in urban aerosols collected during the 2006 Campaign of Air Quality Research in Beijing (CAREBeijing-2006)  

NASA Astrophysics Data System (ADS)

Ground-based studies of PM2.5 were conducted for determination of 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid, during the Campaign of Air Quality Research in Beijing 2006 (CAREBeijing-2006; 21 August to 4 September 2006) at urban (Peking University, PKU) and suburban (Yufa) sites of Beijing. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C2) was the most abundant species, followed by phthalic acid (Ph) and succinic acid (C4) at both sites. The sum of three dicarboxylic acids accounted for 71% and 74% of total quantified water-soluble organics (327-1552 and 329-1124 ng m-3) in PKU and Yufa, respectively. Positive correlation was found between total quantified water-soluble species and water-soluble organic compounds (WSOC). On a carbon basis, total quantified dicarboxylic acids and ketocarboxylic acids and dicarbonyls account for up to 14.2% and 30.4% of the WSOC in PKU and Yufa, respectively, suggesting that they are the major WSOC fractions in Beijing. The distributions of fatty acids are characterized by a strong even carbon number predominance with maximum at hexadecanoic acid (C16:0). The ratio of octadecanoic acid (C18:0) to hexadecanoic acid (C16:0) (0.39-0.85, with an average of 0.36) suggests that in addition to vehicular emissions, an input from cooking emissions is important, as is biogenic emission. Benzoic acid that has been proposed as a primary pollutant from vehicular exhaust and a secondary product from photochemical reactions was found to be abundant: 72.2 58.1 ng m-3 in PKU and 78.0 47.3 ng m-3 in Yufa. According to the 72 hour back trajectory analysis, when the air mass passed over the southern or southeastern part of Beijing (24-25 August and 1-2 September), the highest concentrations of organic compounds were observed. On the contrary, when the clean air masses came straight from the north during 3-4 September, the lowest levels of organic compounds were recorded. This study demonstrates that pollution episodes in Beijing were strongly controlled by wind direction; that is, air quality in Beijing is good when air masses originate from the north and northwest, whereas it deteriorates when the air mass originates from the south and southeast.

Ho, K. F.; Lee, S. C.; Ho, Steven Sai Hang; Kawamura, Kimitaka; Tachibana, Eri; Cheng, Y.; Zhu, Tong

2010-10-01

111

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

PubMed

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. PMID:22959133

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

2012-10-30

112

FT-IR study on the adsorption of benzoic acid and its derivatives on transition-metal oxides  

NASA Astrophysics Data System (ADS)

The present study gives the results of our attempts to gain more knowledge on the interaction between an aromatic carboxylic acid and an oxide catalyst. There is quite a difference in the coordination of benzoic (and salicylic) acid with an acid-base catalyst (?-Al 2O 3) or a redox one (?-Mn 3O 4). When a substituent is incorporated into the ring, the difference becomes even larger. These differences can perhaps explain the difficulties in the catalytic reduction from (substituted) benzoic acids to the corresponding aldehydes.

Koutstaal, C. A.; Ponec, V.

1993-06-01

113

Impact of several water-miscible organic solvents on sorption of benzoic acid by soil  

SciTech Connect

Sorption of benzoic acid by a surface soil was measured from several binary mixtures of water and various organic cosolvents spanning a wide range in solvent properties. For all solvents investigated, the addition to an aqueous solution resulted in an increase in solubility and an alkaline shift in the conditional ionization constant (pK{sub a}{sup c}) of benzoic acid. Sorption data were assessed using a cosolvency model that incorporated speciation of the organic acid as determined by the pK{sub a}{sup c} and soil-solution pH. The model provided reasonable predictions of the sorption trends observed from acetone/water, acetonitrile/ water, and 1,4-dioxane/water solutions. However, enhanced sorption observed from DMSO/water solutions was not well described by the cosolvency model similar to what was previously observed for the sorption of carboxylic acids from methanol/water solutions. The relative importance of cosolvent properties and various solvent-specific mechanisms is discussed. Hydrogen bonding along with preferential solvation are hypothesized as the primary mechanisms responsible for the observed deviations from the model. 36 refs., 5 figs., 1 tab.

Lee, L.S. [Purdue Univ., West Lafayette, IN (United States)] [Purdue Univ., West Lafayette, IN (United States); Rao, P.S.C. [Univ. of Florida, Gainesville, FL (United States)] [Univ. of Florida, Gainesville, FL (United States)

1996-05-01

114

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

115

Participation of a medium chain acyl-CoA synthetase in glycine conjugation of the benzoic acid derivatives with the electron-donating groups  

Microsoft Academic Search

Glycine conjugation of a series of benzoic acid derivatives was investigated in bovine liver mitochondria. Benzoic acids with chlorine, methyl, methoxy, or ethoxy substituents in the para- or metapositions of the benzene ring showed a high degree of glycine conjugation. In contrast, the acids with cyano, nitro, amino, or acetylamino groups were conjugated to a small extent with glycine. A

Fumiyo Kasuya; Kazuo Igarashi; Miyoshi Fukui

1996-01-01

116

Effect of several electrolyzed waters on the skin permeation of lidocaine, benzoic Acid, and isosorbide mononitrate.  

PubMed

The effects of several electrolyzed waters were evaluated on the permeation of model base, acid and non-ionized compounds, lidocaine (LC), benzoic acid (BA), and isosorbide mononitrate (ISMN), respectively, through excised hairless rat skin. Strong alkaline-electrolyzed reducing water (ERW) enhanced and suppressed the skin permeation of LC and BA, respectively, and it also increased the skin permeation of ISMN, a non-ionized compound. On the contrary, strong acidic electrolyzed oxidizing water (EOW) enhanced BA permeation, whereas suppressing LC permeation. Only a marginal effect was observed on the skin permeation of ISMN by EOW. These marked enhancing effects of ERW on the skin permeation of LC and ISMN were explained by pH partition hypothesis as well as a decrease in skin impedance. The present results strongly support that electrolyzed waters, ERW and EOW, can be used as a new vehicle in topical pharmaceuticals or cosmetics to modify the skin permeation of drugs without severe skin damage. PMID:19065312

Kitamura, Toshihiko; Todo, Hiroaki; Sugibayashi, Kenji

2009-02-01

117

Adsorption of benzoic acid on [alpha]-alumina and [gamma]-boehmite  

SciTech Connect

The adsorption of benzoic acid (BzCOOH) on [alpha]-alumina ([alpha]-Al[sub 2]O[sub 3]) and [gamma]-boehmite ([gamma]-AlOOH) from the aqueous phase has been studied. The adsorption experiments were carried out in 0 and 0.1 M NaCl solutions, with pH adjusted to 4 or 6. For both [alpha]-alumina and [gamma]-boehmite, increasing ionic strength decreases the maximum adsorption. Increasing the pH to 6 at the same ionic strength also reduces the maximum adsorption markedly. This suggests that both the anion and the corresponding acid participate in the adsorption process. The results show that benzoic acid has a greater affinity for [alpha]-alumina than for [gamma]-boehmite. Under the same experimental conditions (0.1 M NaCl, pH 4) the maximum adsorption capacities are 5.0 and 1.5 [mu]mol/m[sup 2] for [alpha]-alumina and [gamma]-boehmite, respectively. This difference in adsorption capacities is probably due to the mineralogical difference. These results illustrate the importance of knowing the mineralogical composition of the solid phase.

Madsen, L. (Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Geology and Geotechnical Engineering); Blokhus, A.M. (Univ. of Bergen (Norway). Dept. of Chemistry)

1994-08-01

118

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

PubMed

The search of alternative compounds to control tropical diseases such as schistosomiasis has pointed to secondary metabolites derived from natural sources. Piper species are candidates in strategies to control the transmission of schistosomiasis due to their production of molluscicidal compounds. A new benzoic acid derivative and three flavokawains from Piper diospyrifolium, P. cumanense and P. gaudichaudianum displayed significant activities against Biomphalaria glabrata snails. Additionally, "in silico" studies were performed using docking assays and Molecular Interaction Fields to evaluate the physical-chemical differences among the compounds in order to characterize the observed activities of the test compounds against Biomphalaria glabrata snails. PMID:24762961

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

2014-01-01

119

Induction of benzoic acid 2-hydroxylase in virus-inoculated tobacco  

SciTech Connect

Salicylic acid (SA) plays an important role in the induction of plant resistance to pathogens. An accompanying article shows that SA is synthesized via the decarboxylation of cinnamic acid to benzoic acid (BA), which is, in turn, hydroxylated to SA. Leaf extracts of tobacco catalyze the 2-hydroxylation of Ba to SA. The monooxygenase catalyzing this reaction, benzoic acid 2-hydroxylase (BA2H), required NAD(P)H or reduced methyl viologen as an electron donor. BA2H activity was detected in healthy tobacco leaf extracts (1-2 nmol h[sup [minus]1] g[sup [minus]1] fresh weight) and was significantly increased upon inoculation with tobacco mosaic virus (TMV). This increase paralleled the levels of free SA in the leaves. Induction of BA2H activity was restricted to tissue expressing a hypersensitive response at 24[degrees]C. TMV induction of BA2H activity and Sa accumulation were inhibited when inoculated tobacco plants were incubated for 4 d at 32[degrees]C and then transferred to 24[degrees]C, they showed a 15-fold increase in BA2H activity and a 65-fold increase in free SA content compared with healthy plants incubated at 24[degrees]C. Treatment of leaf tissue with the protein synthesis inhibitor cycloheximide blocked the induction of BA2H activity by TMV. The effect of TMV inoculation on BA2H could be duplicated by infiltrating leaf discs of healthy plants with BA. This response was observed even when applied levels of BA were much lower than the levels observed in vivo after virus inoculation. Feeding tobacco leaves with phenylalanine, cinnamic acid, or o-coumaric acid (putative precursors of SA) failed to trigger the induction of BA2H activity. BA2H appears to be a pathogen-inducible protein with an important regulatory role in SA accumulation during the development of induced resistance to TMV in tobacco. 33 refs., 6 figs., 3 tabs.

Leon, J.; Yalpani, N.; Raskin, I.; Lawton, M.A. (Rutgers Univ., New Brunswick, NJ (United States))

1993-10-01

120

Simultaneous analysis of dehydroacetic acid, benzoic acid, sorbic acid and salicylic acid in cosmetic products by solid-phase extraction and high-performance liquid chromatography.  

PubMed

A high-performance liquid chromatographic (HPLC) method for simultaneous determination of dehydroacetic acid (DHA), benzoic acid (BA), sorbic acid (SOA) and salicylic acid (SA) was developed for application to cosmetic products. Isocratic reversed-phase HPLC was employed for quantitative analysis using tetra-n-butylammonium (TBA) hydroxide as an ion-pair reagent. Cosmetic samples were purified by solid-phase extraction using Bond-Elut SI cartridges. Four acidic preservatives were eluted with methanol from cartridges. The HPLC assay was carried out using TSK gel ODS-80TM column (5 microm, 150 x 4.6 mm I.D.). The mobile phase consisted of a mixture of water and methanol (65:35, v/v) containing 2.5 mM TBA hydroxide adjusted with phosphoric acid to pH 7.0. The calibration curves of these preservatives showed good linearity with UV detection (235 nm). The correlation coefficients were better than 0.999 in all cases. The lower limits of detection (defined as a signal-to-noise ratio of about 3) were approximately 2.5 ng for DHA, 4.0 ng for BA, 2.0 ng for SOA and 5.5 ng for SA. The procedure described here is simple, selective and is suitable for quality control of finished cosmetic products. PMID:11929668

Mikami, E; Goto, T; Ohno, T; Matsumoto, H; Nishida, M

2002-04-15

121

The electroreduction of benzoic acid: voltammetric observation of adsorbed hydrogen at a platinum microelectrode in room temperature ionic liquids.  

PubMed

The electrochemical reduction of benzoic acid in the presence and absence of hydrogen (H(2)) has been investigated using a 10 ?m diameter platinum microelectrode in four different room temperature ionic liquids (RTILs), namely [C(4)mim][NTf(2)], [C(4)mpyrr][NTf(2)], [C(4)mim][OTf] and [C(4)mim][BF(4)], versus Ag/Ag(+). In all cases, reductive voltammetry is observed, and is suggested to occur via a CE mechanism in which dissociation of benzoic acid is followed by electron transfer to H(+) ultimately forming adsorbed hydrogen. Furthermore, the adsorbed H atoms, formed from the reduction of benzoic acid, could be used to achieve the rapid hydrogenolysis of the organic compound (bis(benzyloxycarbonyl)-l-lysine) on the timescale of the voltammetric technique under moderate conditions (25 C). PMID:23262562

Meng, Yao; Norman, Sarah; Hardacre, Christopher; Compton, Richard G

2013-02-14

122

Cyclodextrin-benzoic acid binding in salt solutions: Effects of biologically relevant anions.  

PubMed

Inclusion complex formation of benzoic acid with ?-, ?- and ?-cyclodextrins in water and in 0.2M solutions of inorganic salts (KCl, KBr, KH2PO4 and K2SO4) has been studied by means of (1)H NMR at 298.15K. Binding constants have been determined and role of biologically active inorganic anions in the inclusion complex formation has been revealed. It has been shown that effects of the anions are determined not only by changing the ionic strength. More pronounced influence of Br(-) and H2PO4(-) compared with Cl(-) and SO4(2-) is caused by specific ion-molecular interactions, occurrence of which depends on the physical-chemical properties of the anions as well as on the binding mode of cyclodextrins with benzoic acid. Competing interactions of cyclodextrin-anion were observed in the presence of KBr, while the ternary complex formation was detected upon addition of KH2PO4. PMID:24906781

Terekhova, I V; Chibunova, E S; Kumeev, R S; Alper, G A

2014-09-22

123

Time-dependent density functional theory assessment of UV absorption of benzoic acid derivatives.  

PubMed

Benzoic acid (BA) derivatives of environmental relevance exhibit various photophysical and photochemical characteristics. Here, time-dependent density functional theory (TDDFT) is used to calculate photoexcitations of eight selected BAs and the results are compared with UV spectra determined experimentally. High-level gas-phase EOM-CCSD calculations and experimental aqueous-phase spectra were used as the references for the gas-phase and aqueous-phase TDDFT results, respectively. A cluster-continuum model was used in the aqueous-phase calculations. Among the 15 exchange-correlation (XC) functionals assessed, five functionals, including the meta-GGA hybrid M06-2X, double hybrid B2PLYPD, and range-separated functionals CAM-B3LYP, ?B97XD, and LC-?PBE, were found to be in excellent agreement with the EOM-CCSD gas-phase calculations. These functionals furnished excitation energies consistent with the pH dependence of the experimental spectra with a standard deviation (STDEV) of ?0.20 eV. A molecular orbital analysis revealed a ??* feature of the low-lying transitions of the BAs. The CAM-B3LYP functional showed the best overall performance and therefore shows promise for TDDFT calculations of processes involving photoexcitations of benzoic acid derivatives. PMID:23134517

Guo, Hao-Bo; He, Feng; Gu, Baohua; Liang, Liyuan; Smith, Jeremy C

2012-12-01

124

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

PubMed

Ex vivo perfusion of the human term placenta is a method to study placental transfer without extrapolation from animal to human and with no ethical concerns for mother and child. However, ex vivo placenta perfusion has a limited potential within chemical screening and testing as the method is time-consuming. This study was an attempt to construct data needed to develop quantitative structure-activity relationship (QSAR) models that are able to predict placental transfer of new compounds. Placental transfer is a biological activity that statistically may be related to the physiochemical properties of a given 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. PMID:18569607

Mose, Tina; Kjaerstad, Mia Birkhoej; Mathiesen, Line; Nielsen, Jesper Bo; Edelfors, Sven; Knudsen, Lisbeth E

2008-01-01

125

Reaction between anthranilic acids, salicylaldehydes and isocyanides in water: an efficient synthesis of 2-{[2-(alkylimino)-1-benzofuran-3-yliden]amino}benzoic acids  

Microsoft Academic Search

A novel, one-pot and three-component reaction for the preparation of 2-{[2-(alkylimino)-1-benzofuran-3-yliden]amino}benzoic acids is described. Heating a mixture of an anthranilic acid, a salicylaldehyde, and an isocyanide in water affords the title compounds in good to excellent yields.

Mehdi Adib; Mohammad Mahdavi; Sharareh Bagherzadeh; Long-Guan Zhu; Mehdi Rahimi-Nasrabadi

2010-01-01

126

Free and Conjugated Benzoic Acid in Tobacco Plants and Cell Cultures. Induced Accumulation upon Elicitation of Defense Responses and Role as Salicylic Acid Precursors  

Microsoft Academic Search

Salicylic acid (SA) is a key endogenous component of local and systemic disease resistance in plants. In this study, we investigated the role of benzoic acid (BA) as precursor of SA biosynthesis in tobacco (Nicotiana tabacum cv Samsun NN) plants undergoing a hypersensitive response following infection with tobacco mosaic virus or in tobacco cell suspensions elicited with b-megaspermin, an elicitor

Julie Chong; Marie-Agnes Pierrel; Rossitza Atanassova; Daniele Werck-Reichhart; Bernard Fritig; Patrick Saindrenan

2001-01-01

127

Accumulation of benzoic acid in suspension cultured cells of Pinus thunbergii Parl. in response to phenylacetic acid administration.  

PubMed

The generation and accumulation of both benzoic acid (BA) and its conjugates were induced in suspension cultured cells of Pinus thunbergii by administering either phenylacetic acid (PA), a toxic metabolite of Bacillus cereus (strain HY-3) accompanying the pine wood nematode, or a lyophilized culture supernatant of this bacterium. BA conjugates reached their maximal levels in quantity two days after the administration and then decreased gradually until the 14th day, while BA increased significantly throughout this period. This pattern is similar to that in 3-year-old pine trees treated with PA, suggesting that the pathological reaction of pine tissues to the PA toxin might be involved in the pathogenesis mechanism for the pine wilt disease. PMID:8987587

Kawazu, K; Zhang, H; Kanzaki, H

1996-09-01

128

Complex formation of native and hydroxypropylated cyclodextrins with benzoic acid in aqueous solution: Volumetric and 1H NMR study  

NASA Astrophysics Data System (ADS)

Novel data on complexation of benzoic acid by parent and hydroxypropylated cyclodextrins were obtained by densimetry and 1H NMR. Formation of 1:1 inclusion complexes was detected in most cases with the exception of hydroxypropyl-?-cyclodextrin, which is able to form 1:2 complexes. The data demonstrated penetration of carboxylic group of benzoic acid inside macrocyclic cavity, its insertion into ?-cyclodextrin cavity being deeper. Binding constants and volumes of transfer were calculated and analyzed in terms of influence of cyclodextrin structure on binding mode and driving forces of interaction as well as on the complex stability.

Terekhova, Irina; Ko?bia?, Malgorzata; Kumeev, Roman; Gierycz, Pawe?

2011-10-01

129

40 CFR 721.1550 - Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1).  

Code of Federal Regulations, 2010 CFR

...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1). 721.1550...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1). (a)...

2009-07-01

130

40 CFR 721.1550 - Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1).  

Code of Federal Regulations, 2010 CFR

...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1). 721.1550...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1). (a)...

2010-07-01

131

Identification of bisprenylated benzoic acid derivatives from yerba santa (Eriodictyon ssp.) using sensory-guided fractionation.  

PubMed

Due to certain off-flavor problems and lacking bitter masking effects with Yerba Santa (Eriodictyon angustifolium and E. californicum) extracts, which are also described as bitter, herbal, medicinal, phenolic, or astringent, methanolic extracts were fractionated and evaluated for their taste properties using a high temperature liquid chromatography (HTLC)-based approach. The taste-guided fractionation led to the identification of a series of novel bisprenylated benzoic acids (erionic acids A (1), B (2), C (3), D (4), E (5), and F (6) and eriolic acids A (7), B (8), C (9), and D (10), respectively), along with the known flavonoids eriodictyol, homoeriodictyol, hesperetin, and chrysoeriol. The new compounds were isolated in larger amounts for characterization from Narrow Leaf Yerba Santa (E. angustifolium) and California Yerba Santa (E. californicum), respectively, using fast centrifugal partition chromatography (FCPC) and HTLC. The structures were elucidated using one and two-dimensional NMR spectroscopy and high resolution mass spectrometry (HR-MS). For E. californicum, data regarding seasonal and climatic variation of the eriolic acid contents and of the flavonoids were collected. The flavor properties of some of the isolated new compounds were evaluated; they showed strong off-flavor characteristics, such as bitter, astringent, phenolic, or woody, and may contribute to the sensory effects observed for crude Yerba Santa extracts. Erionic acid C (3) was not only able to increase the absolute bitterness but also to extinguish the bitter masking effect of homoeriodictyol in a caffeine solution. PMID:20058867

Reichelt, Katharina V; Hartmann, Beate; Weber, Berthold; Ley, Jakob P; Krammer, Gerhard E; Engel, Karl-Heinz

2010-02-10

132

Orientation and bonding of benzoic acid, phthalic anhydride and pyromellitic dianhydride on Cu(110)  

NASA Astrophysics Data System (ADS)

The interaction of the polyimide precursor pyromellitic dianhydride (PMDA), and the related compounds benzoic acid and phthalic anhydride, with Cu(110) has been studied by high resolution electron energy loss spectroscopy (HREELS). For benzoic acid, deprotonation of the carboxylic acid group occurs on adsorption leading to the formation of a surface benzoate species (C 6H 5COO-). Bonding to the surface occurs through a carboxylate linkage via two equivalent oxygen atoms. The HREEL spectrum is characterised by an intense dipole active band, the symmetric O?C?O stretching vibration, at 1420 cm -1. The plane of the carboxylate group is aligned perpendicular to the surface as is the plane of the benzene ring. A similar species is found following exposure of Cu(110) to phthalic anhydride. The carboxylate linkage results from disruption of the anhydride ring with loss of the C?O character (C 6H 4COO-). In the case of the dianhydride species PMDA, only one of the anhydride units is used in bonding to the surface; the second unit points away from the surface and is characterised by the symmetric anhydride stretch at 1255 cm -1 and weak OO stretching vibrations at 1850 cm -1. In both cases, changes in the intensity of some of the bands compared with benzoic acid suggest that the carboxylate group is tilted away from the surface normal due to an interaction between one of the carbons of the aromatic ring and the copper surface. This implies that the plane of the aromatic ring is now twisted out of the plane of the carboxylate group and, although still perpendicular to the surface, the axis is tilted to allow one of the ?-carbon atoms to interact with the surface. In all cases, off-specular measurements at a primary electron energy of 8 eV are dominated by the intense C?H stretching vibration. Measurements of the intensity of this mode, in the surface benzoate species, as a function of incident electron energy suggest that excitation of this mode occurs via a resonance scattering mechanism.

Frederick, B. G.; Ashton, M. R.; Richardson, N. V.; Jones, T. S.

1993-07-01

133

DFT and ab initio study of structure of dyes derived from 2-hydroxy and 2,4-dihydroxy benzoic acids  

NASA Astrophysics Data System (ADS)

We present a detailed analysis of the structural, infrared spectra and visible spectra of a series of azo dyes preparation of salicylic acid and 2,4-dihydroxy benzoic acid derivatives as the coupling component. The preparation of these azo dyes with salicylic acid and 2,4-dihydroxy benzoic acid derivatives (salicylic acid, methyl salicylate, ethyl salicylate, butyl salicylate, methyl 2,4-dihydroxy benzoate, ethyl 2,4-dihydroxy benzoate, salicylaldehyde, salicylamide, 2,4-dihydroxy benzamide, salicylaldoxime) have been investigated theoretically by performing HF and DFT levels of theory using the standard 6-31G* basis set. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. The vibrational spectral data obtained from solid phase FT-IR spectra are assigned modes based on the results of the theoretical calculations. The observed spectra are found to be in good agreement with the calculations.

Dabbagh, Hossein A.; Teimouri, Abbas; Najafi Chermahini, Alireza; Shahraki, Maryam

2008-02-01

134

Induction of Benzoic Acid 2-Hydroxylase in Virus-Inoculated Tobacco.  

PubMed Central

Salicylic acid (SA) plays an important role in the induction of plant resistance to pathogens. An accompanying article (N. Yalpani, J. Leon, M.A. Lawton, I. Raskin [1993] Plant Physiol 103: 315-321) shows that SA is synthesized via the decarboxylation of cinnamic acid to benzoic acid (BA), which is, in turn, hydroxylated to SA. Leaf extracts of tobacco (Nicotiana tabacum L. cv Xanthi-nc) catalyze the 2-hydroxylation of BA to SA. The monooxygenase catalyzing this reaction, benzoic acid 2-hydroxylase (BA2H), required NAD(P)H or reduced methyl viologen as an electron donor. BA2H activity was detected in healthy tobacco leaf extracts (1-2 nmol h-1 g-1 fresh weight) and was significantly increased upon inoculation with tobacco mosaic virus (TMV). This increase paralleled the levels of free SA in the leaves. Induction of BA2H activity was restricted to tissue expressing a hypersensitive response at 24[deg]C. TMV induction of BA2H activity and SA accumulation were inhibited when inoculated tobacco plants were incubated at 32[deg]C. However, when inoculated plants were incubated for 4 d at 32[deg]C and then transferred to 24[deg]C, they showed a 15-fold increase in BA2H activity and a 65-fold increase in free SA content compared with healthy plants incubated at 24[deg]C. Treatment of leaf tissue with the protein synthesis inhibitor cycloheximide blocked the induction of BA2H activity by TMV. The effect of TMV inoculation on BA2H could be duplicated by infiltrating leaf discs of healthy plants with BA. This response was observed even when applied levels of BA were much lower than the levels observed in vivo after virus inoculation. Feeding tobacco leaves with phenylalanine, cinnamic acid, or o-coumaric acid (putative precursors of SA) failed to trigger the induction of BA2H activity. BA2H appears to be a pathogen-inducible protein with an important regulatory role in SA accumulation during the development of induced resistance to TMV in tobacco.

Leon, J.; Yalpani, N.; Raskin, I.; Lawton, M. A.

1993-01-01

135

Reactions of Supercritical Water with Benzaldehyde, Benzylidenebenzylamine, Benzyl Alcohol, and Benzoic Acid. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

This paper describes the results of reactions of benzaldehyde, benzyl alcohol, benzoic acid, and benzylidenebenzylamine (C6H5CH2N=CHC6H5) With supercritical water (SW) since these compounds were determined or assumed to be major intermediates in the react...

C. C. Tsao Y. Zhou X. Liu T. J. Huser

1992-01-01

136

A platinum(II) complex bearing deprotonated 2-(diphenylphosphino)benzoic acid for superior phosphorescence of monomers.  

PubMed

The (ppy)-based Pt(II) complex (Pt-1) with deprotonated 2-(diphenylphosphino)benzoic acid as an anionic ligand displays phosphorescence of monomers with a remarkably higher quantum yield than that of the corresponding iridium complex (Ir-1). A prototype OLED using Pt-1 exhibits high performance with an external quantum efficiency of 4.93%. PMID:24718420

Zhang, Bin; Zhang, Lina; Liu, Chunmei; Zhu, Yanyan; Tang, Mingsheng; Du, Chenxia; Song, Maoping

2014-06-01

137

In vitro predictions of skin absorption of caffeine, testosterone, and benzoic acid: a multi-centre comparison study  

Microsoft Academic Search

To obtain better insight into the robustness of in vitro percutaneous absorption methodology, the intra- and inter-laboratory variation in this type of study was investigated in 10 European laboratories. To this purpose, the in vitro absorption of three compounds through human skin (9 laboratories) and rat skin (1 laboratory) was determined. The test materials were benzoic acid, caffeine, and testosterone,

J. J. M. van de Sandt; J. A. van Burgsteden; S. Cage; P. L. Carmichael; I. Dick; S. Kenyon; G. Korinth; F. Larese; J. C. Limasset; W. J. M. Maas; L. Montomoli; J. B. Nielsen; J.-P. Payan; E. Robinson; P. Sartorelli; K. H. Schaller; S. C. Wilkinson; F. M. Williams

2004-01-01

138

Anaerobic degradation of halogenated benzoic acids coupled to denitrification observed in a variety of sediment and soil samples  

Microsoft Academic Search

Denitrifying enrichment cultures utilizing monochlorinated benzoic acids as a carbon source were established using sediments and soils from a variety of sources as inocula. Enrichment cultures from most of the sites readily degraded 3- and 4chlorobenzoate within 24 weeks. Upon refeeding, 3- and 4-chlorobenzoate were rapidly depleted, and stable denitrifying cultures were obtained by repeated dilution and refeeding of the

Max M. Hggblom; Maria D. Rivera; Lily Y. Young

1996-01-01

139

Influence of alternative electron acceptors on the anaerobic biodegradability of chlorinated phenols and benzoic acids  

SciTech Connect

Nitrate, sulfate, and carbonate were used as electron acceptors to examine the anaerobic biodegradability of chlorinated aromatic compounds in estuarine and freshwater sediments. The respective denitrifying, sulfidogenic, and methanogenic enrichment cultures were established on each of the monochlorinated phenol and monochlorinated benzoic acid isomers, using sediment from the upper (freshwater) and lower (estuarine) Hudson River and the East River (estuarine) as source materials. Utilization of each chlorophenol and chlorobenzoate isomer was observed under at least one reducing condition; however, no single reducing condition permitted the metabolism of all six compounds tested. The anaerobic biodegradation of the chlorophenols and chlorobenzoates depended on the electron acceptor available and on the position of the chlorine substituent. In general, similar activities were observed under the different reducing conditions in both the freshwater and estuarine sediments.

Haeggblom, M.M.; Rivera, M.D.; Young, L.Y.

1993-01-01

140

Oxidation of benzaldehydes to benzoic acid derivatives by three Desulfovibrio strains.  

PubMed Central

Desulfovibrio vulgaris Marburg, "Desulfovibrio simplex" XVI, and Desulfovibrio sp. strain MP47 used benzaldehydes such as vanillin, 3,4,5-trimethoxybenzaldehyde, protocatechualdehyde, syringaldehyde, p-anisaldehyde, p-hydroxybenzaldehyde, and 2-methoxybenzaldehyde as electron donors for sulfate reduction and carbon dioxide and/or components of yeast extract as carbon sources for cell synthesis. The aldehydes were oxidized to their corresponding benzoic acids. The three sulfate reducers oxidized up to 7 mM vanillin and up to 4 mM p-anisaldehyde. Higher concentrations of vanillin or p-anisaldehyde were toxic. In addition, pyridoxal hydrochloride and o-vanillin served as electron donors for sulfate reduction. Salicylaldehyde, pyridine-2-aldehyde, pyridine-4-aldehyde, and 4-hydroxy-3-methoxybenzylalcohol were not oxidized. No molecular hydrogen was detected in the gas phase. The oxidized aldehydes were not further degraded.

Zellner, G; Kneifel, H; Winter, J

1990-01-01

141

Effects of toluene and benzoic acid on the kinetics of ferrous oxidation on Pt and nafion-coated Pt electrodes  

SciTech Connect

The electrochemical kinetics of Fe[sup 2+] oxidation to Fe[sup 3+] have been investigated by cyclic and ring disk electrode voltammetry in the absence and presence of the contaminants toluene (7 mM, saturated solution) or benzoic acid (16 mM) in 1M H[sub 2]SO[sub 4] electrolyte on (1) smooth Pt electrodes, (2) Nafion-coated smooth Pt electrodes, and (3) Pt electrodes electrodeposited within a Nafion film coated onto a glassy carbon (GC) substrate. On uncoated Pt, the kinetics are adversely affected by these two organics: both the anodic transfer coefficient and the apparent standard rate constant are decreased. A 3.7 [mu]m Nafion coating, however, effectively buffers the smooth Pt electrode from toluene, but, nevertheless, benzoic acid still affects the reaction rate. In contrast, the transfer coefficient and rate constant for Fe[sup 2+] oxidation on the Pt/Nafion/GC electrode are essentially unaffected by either toluene or benzoic acid. Qualitative features of the voltammograms also indicate that the Nafion film protects the Pt from contamination by these aromatics: two current plateaus are observed using an uncoated Pt electrode in the presence of toluene or benzoic acid with a ratio which increased with rotation rate; with the Nafion coating on a smooth Pt electrode and in the presence of toluene, however, there is only one current plateau; in the presence of benzoic acid, two current plateaus remain, but the ratio is nearer unity and less sensitive to rotation rate. In contrast, only a single plateau current is observed using the Pt/Nafion/GC electrode. The Nafion coating is apparently an effective buffer layer against these two aromatics, but concurrently affects a decrease in the mass-transfer limited current due to the diffusional resistance of the film.

Ye, J.H.; Fedkiw, P.S. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemical Engineering)

1994-06-01

142

Synthesis of 5-nitro-2-(N-3-(4-azidophenyl)-propylamino)-benzoic acid: Photoaffinity labeling of human red blood cell ghosts with a 5-nitro-2-(3-phenylpropylamino)-benzoic acid analog  

SciTech Connect

A photoaffinity analog of the potent epithelial chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoic acid has been synthesized and characterized. In the dark, this reagent, 5-nitro-2-(N-3-(4-azidophenyl)-propylamino)-benzoic acid, and the parent compound reversibly inhibited chloride efflux in human red blood cell ghosts. Irradiation of ghost membranes with 350 microM arylazide analog reduced the rate of chloride efflux to 33% of the control value. The photoinactivation process was not reversed by exhaustive washing of ghost membranes. Covalent incorporation of the photoaffinity reagent was supported by difference ultraviolet spectroscopy, which indicated the attachment of the substituted 2-amino-5-nitrobenzoic acid chromophore to ghost membranes. The novel photolabeling agent described here should be a useful structural probe for chloride channels in erythrocyte membranes and epithelial cells.

Branchini, B.R.; Murtiashaw, M.H.; Egan, L.A. (Connecticut Coll., New London (USA))

1991-04-15

143

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  

PubMed Central

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.

Giannenas, I.; Papaneophytou, C. P.; Tsalie, E.; Pappas, I.; Triantafillou, E.; Tontis, D.; Kontopidis, G. A.

2014-01-01

144

Development of an RP-HPLC method for the simultaneous determination of benzoic acid, sorbic acid, natamycin and lysozyme in hard and pasta filata cheeses  

Microsoft Academic Search

A single method, based on RP-HPLC with UV detection, was developed with the aim of simultaneously quantifying four preservatives in cheeses: benzoic acid, sorbic acid, natamycin and lysozyme.The preservatives were extracted from different cheeses by using the same procedure, and separated by a single RP-HPLC gradient elution showing good resolution, in a short time.Recoveries were always higher than 91%; MDLs

Chiara Guarino; Fabio Fuselli; Alessandro La Mantia; Lucia Longo

2011-01-01

145

Completion of the core ?-oxidative pathway of benzoic acid biosynthesis in plants.  

PubMed

Despite the importance of benzoic acid (BA) as a precursor for a wide array of primary and secondary metabolites, its biosynthesis in plants has not been fully elucidated. BA formation from phenylalanine requires shortening of the C(3) side chain by two carbon units, which can occur by a non-?-oxidative route and/or a ?-oxidative pathway analogous to the catabolism of fatty acids. Enzymes responsible for the first and last reactions of the core BA ?-oxidative pathway (cinnamic acid ? cinnamoyl-CoA ? 3-hydroxy-3-phenylpropanoyl-CoA ? 3-oxo-3-phenylpropanoyl-CoA ? BA-CoA) have previously been characterized in petunia, a plant with flowers rich in phenylpropanoid/benzenoid volatile compounds. Using a functional genomics approach, we have identified a petunia gene encoding cinnamoyl-CoA hydratase-dehydrogenase (PhCHD), a bifunctional peroxisomal enzyme responsible for two consecutively occurring unexplored intermediate steps in the core BA ?-oxidative pathway. PhCHD spatially, developmentally, and temporally coexpresses with known genes in the BA ?-oxidative pathway, and correlates with emission of benzenoid volatiles. Kinetic analysis of recombinant PhCHD revealed it most efficiently converts cinnamoyl-CoA to 3-oxo-3-phenylpropanoyl-CoA, thus forming the substrate for the final step in the pathway. Down-regulation of PhCHD expression in petunia flowers resulted in reduced CHD enzyme activity, as well as decreased formation of BA-CoA, BA and their derived volatiles. Moreover, transgenic lines accumulated the PhCHD substrate cinnamoyl-CoA and the upstream pathway intermediate cinnamic acid. Discovery of PhCHD completes the elucidation of the core BA ?-oxidative route in plants, and together with the previously characterized CoA-ligase and thiolase enzymes, provides evidence that the whole pathway occurs in peroxisomes. PMID:22988098

Qualley, Anthony V; Widhalm, Joshua R; Adebesin, Funmilayo; Kish, Christine M; Dudareva, Natalia

2012-10-01

146

In vitro effects of quercetin on oxidative stress mediated in human erythrocytes by benzoic acid and citric acid.  

PubMed

Benzoic acid (BA) and citric acid (CA) are food additives commonly used in many food products. Food additives play an important role in food supply but they can cause various harmful effects. The in vitro adverse effects of BA and CA and the protective effect of quercetin on human erythrocytes were investigated by measuring malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities. Erythrocytes were incubated with BA and CA, at three doses of 50, 100 and 200 microg/ml, and quercetin, at a concentration of 10 microM. After BA and CA application, a dose-dependent increase in MDA level and decreases in SOD, CAT, GST and GPx activities were found in erythrocytes. Among the two food additives, BA exerted a more harmful influence on human erythrocytes than CA. The protective effects of quercetin against oxidative stress--induction in the human erythrocytes by CA and BA, were found when these two food additives were applied at each of three doses of 50, 100 and 200 microg/ml. However, complete protection of quercetin against CA toxicity was only observed when this agent was applied at a lower dose of 50 microg/ml. Quercetin did not completely protect erythrocytes even at the lowest concentration of BA. PMID:24745150

Ba?, Hatice; Kalender, Suna; Pandir, Dilek

2014-01-01

147

4-Nitro-benzoic acid-sulfa-thia-zole (1/1)  

PubMed Central

In the crystal structure of the title compound, C7H5NO4C9H9N3O2S2, the sulfathiazole and 4-nitrobenzoic acid molecules are held together by short ?? contacts between the thiazole and nitrobenzene rings, with a centroidcentroid distance of 3.8226?(7)?. The sulfathiazole molecules form dimers via NH?N hydrogen bonds involving the thiazole and sulfonamide moieties, owing to the fact that sulfathizole exhibits amideimide tautomerism. The NH (amine) groups of two sulfathiazole molecules are linked to the two S=O groups of a sulfathiazole via NH?O hydrogen bonds. Two molecules of coformer are held together by OH?O hydrogen bonds. These units self-assemble, forming a three-dimensional network stabilized by (acid)CH??(sulfathiazole benzene ring) interactions.

Oruganti, Madhavi; Trivedi, Darshak R.

2014-01-01

148

Chemiluminescence of benzoic and cinnamic acids, and flavonoids in the presence of aldehyde and hydrogen peroxide or hydroxyl radical by fenton reaction  

Microsoft Academic Search

Light emission (chemiluminescence; CL) was observed by exciting phenolic compounds with hydrogen peroxide (H2O2) or hydroxyl radical (HO), formed from H2 and FeCl2 by the Fenton reaction. The intensity of the CL of benzoic acid derivatives in the presence of (H2 was in the order of gallic acid > caffeic acid > 3,5-dimethoxy-4-hydroxycinnamic acid > isovanillic acid = syringic acid.

Yumiko Yoshiki; Kazuyoshi Okubo; Masamichi Onuma; Kiharu Igarashi

1995-01-01

149

Benzoic acid and phenol derivatives of nitronyl nitroxide biradical as building blocks of organic molecule-based ferrimagnets  

Microsoft Academic Search

A crystal-engineering approach to organic ferrimagnets is reported. Coulombic energy between an anionic biradical withS = 1 and a cationic monoradical withS = 1\\/2 can be utilized as a driving force of cocrystallization of open-shell molecules with different spin quantum numbers,\\u000a leading to organic salt ferrimagnets. In this study, 3,5-substituted phenol and benzoic acid derivatives of nitronyl nitroxide\\u000a biradicals were

K. Kamiyama; D. Shiomi; S. Hase; M. Nishizawa; K. Sato; M. Kozaki; K. Okada; T. Takui

2000-01-01

150

Induction of functional cytochrome P450 and its involvement in degradation of benzoic acid by Phanerochaete chrysosporium  

Microsoft Academic Search

The white rot fungus Phanerochaete chrysosporium has the largest cytochrome P450 contingent known to date in fungi, but the study on the function of these P450s is limited.\\u000a In this study, induction of functional P450 in P. chrysosporium was first shown and P450-mediate degradation of benzoic acid was demonstrated in this fungus. Carbon monoxide difference\\u000a spectra indicated significant induction of

Daliang NingHui; Hui Wang; Yuan Zhuang

2010-01-01

151

Three-dimensional radiation dose measurements with Ferrous Benzoic Acid Xylenol Orange in Gelatin gel and optical absorption tomography  

Microsoft Academic Search

The optical characteristics of a Ferrous Benzoic Acid Xylenol Orange in Gelatin (FBXG) gel have been studied over the wavelength range 300700nm as a function of radiation dose. The unirradiated gel exhibits a strong absorption peak at 440nm; with increasing dose this peak starts to reduce in intensity while a new broad peak centred at 585nm begins to appear. Using

M. A Bero; W. B Gilboy; P. M Glover; J. L Keddie

1999-01-01

152

Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column  

Microsoft Academic Search

The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method.In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography

Dalibor atnsk; Jitka Huclov; Raquel L. C. Ferreira; Maria Conceio B. S. M. Montenegro; Petr Solich

2006-01-01

153

Enantioselective cycloisomerization of 1,6-enynes to bicyclo[3.1.0]hexanes catalyzed by rhodium and benzoic acid.  

PubMed

It has been established that a cationic Rh(I)/(S)-Segphos or (S)-DTBM-Segphos complex and benzoic acid catalyze the enantioselective cycloisomerization of 1,6-enynes, possessing carbonyl groups at the enyne linkage, to 2-alkylidenebicyclo[3.1.0]hexanes. The present cycloisomerization may involve site selective ?-hydrogen elimination. The one-pot enantioselective cycloisomerization and lactonization of 1,6-enynes, leading to bicyclic lactones, has also been accomplished. PMID:24823870

Masutomi, Koji; Noguchi, Keiichi; Tanaka, Ken

2014-05-28

154

Cellular and Subcellular Localization of S-Adenosyl-L-Methionine:Benzoic Acid Carboxyl Methyltransferase, the Enzyme Responsible for Biosynthesis of the Volatile Ester Methylbenzoate in Snapdragon Flowers  

Microsoft Academic Search

The benzenoid ester, methylbenzoate is one of the most abundant scent compounds detected in the majority of snapdragon (Antirrhinum majus) varieties. It is produced in upper and lower lobes of petals by enzymatic methylation of benzoic acid in the reaction catalyzed by S-adenosyl-l-methionine:benzoic acid carboxyl methyltransferase (BAMT). To identify the location of methylbenzoate biosynthesis, we conducted an extensive immunolocalization study

Natalia Kolosova; Debra Sherman; Dale Karlson; Natalia Dudareva

2001-01-01

155

Influence of alternative electron acceptors on the anaerobic biodegradability of chlorinated phenols and benzoic acids.  

PubMed Central

Nitrate, sulfate, and carbonate were used as electron acceptors to examine the anaerobic biodegradability of chlorinated aromatic compounds in estuarine and freshwater sediments. The respective denitrifying, sulfidogenic, and methanogenic enrichment cultures were established on each of the monochlorinated phenol and monochlorinated benzoic acid isomers, using sediment from the upper (freshwater) and lower (estuarine) Hudson River and the East River (estuarine) as source materials. Utilization of each chlorophenol and chlorobenzoate isomer was observed under at least one reducing condition; however, no single reducing condition permitted the metabolism of all six compounds tested. The anaerobic biodegradation of the chlorophenols and chlorobenzoates depended on the electron acceptor available and on the position of the chlorine substituent. In general, similar activities were observed under the different reducing conditions in both the freshwater and estuarine sediments. Under denitrifying conditions, degradation of 3- and 4-chlorobenzoate was accompanied by nitrate loss corresponding reasonably to the stoichiometric values expected for complete oxidation of the chlorobenzoate to CO2. Under sulfidogenic conditions, 3- and 4-chlorobenzoate, but not 2-chlorobenzoate, and all three monochlorophenol isomers were utilized, while under methanogenic conditions all compounds except 4-chlorobenzoate were metabolized. Given that the pattern of activity appears different for these chlorinated compounds under each reducing condition, their biodegradability appears to be more a function of the presence of competent microbial populations than one of inherent molecular structure.

Haggblom, M M; Rivera, M D; Young, L Y

1993-01-01

156

Wavelength-dependent photodissociation of benzoic acid monomer in alpha C-O fission.  

PubMed

In concert with the latest laser-induced fluorescence (LIF) experiment [Wei et al. J. Phys. Chem. A 2008, 112, 4727], we investigated the photodissociation mechanics of the benzoic acid monomer (BAM) with alpha C-O fission by means of state-of-the-art ab initio calculations. Complete active space self-consistent-field (CASSCF) and multireference CASSCF second-order perturbation theory (MSCASPT2) calculations were performed on the ground and a number of low-lying excited states of BAM. Our calculations indicated that alpha C-O fission from the S(1) state is in competition with the fission from the T(2) state upon the 266-284 nm wavelength photon. This differs from the conclusion of the previous theoretical investigation and clarified the vague experimental conclusion made earlier. According to our calculations, alpha C-O fission mainly occurs at the T(2) state upon photoexcitation at 284-294 nm, and the photon with a wavelength longer than 294 nm is unable to present the alpha C-O fission. This conclusion agrees with the LIF experimental observation. PMID:20020709

Fang, Qiu; Liu, Ya-Jun

2010-01-14

157

Stable Isotope Labeled 4-(Dimethylamino)benzoic Acid Derivatives of Glycerophosphoethanolamine Lipids  

PubMed Central

A set of four (d0, d4, d6, and d10) deuterium enriched 4-(dimethylamino)benzoic acid (DMABA) N-hydroxysuccinimide (NHS) ester reagents was developed that react with the primary amine group of glycerophosphoethanolamine (PE) lipids to create derivatives where all subclasses of DMABA labeled PE are detected by a common precursor ion scan. The positive ion collision induced dissociation data from (d0, d4, d6, and d10)-DMABA labeled PE standards indicated that a precursor ion scan of m/z 191.1, 195.1, 197.1, and 201.1 could be used to selectively detect (d0, d4, d6, and d10)-DMABA modified PE, respectively, in a complex biological mixture. The PE lipids from a time course (0, 30, 60, and 300 min) of AAPH treatment of liposomes made of RAW 264.7 cell phospholipids were each labeled with the d0-, d4-, d10-, and d6-DMABA NHS ester reagents, respectively. The DMABA derivatives revealed loss of endogenous PE lipids and an increase in oxidized PE lipid throughout the time course of AAPH treatment. These DMABA NHS ester reagents provide a universal scan for diacyl, ether, and plasmalogen PE lipids that can not be readily observed otherwise, enable differential labeling, and provide an internal standard for each PE lipid.

Berry, Karin A. Zemski; Turner, William W.; VanNieuwenhze, Michael S.; Murphy, Robert C.

2010-01-01

158

Investigation of monolayer dispersion of benzoic acid supported on the surface of H-titanate nanotubes  

NASA Astrophysics Data System (ADS)

Benzoic acid (BA) can disperse spontaneously onto the surface of H-titanate nanotubes (HTNTs) in a sub-monolayer state by heating mechanical mixtures method. The structure of BA-HTNTs system has been characterized by X-ray diffraction (XRD), thermogravimetric (TG), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) in detail. The results show that the H-bond association structure among BA molecules collapses and the carboxyl groups react with the surface hydroxyl group of HTNTs to form a salt-like structure on the surface after dispersion. The monolayer dispersion capacity determined by XRD is ca. 0.305 g BA g -1 HTNTs, which is lower than the utmost monolayer dispersion capacity 0.550 g BA g -1 HTNTs calculated according to a model that the benzene ring in BA molecules is perpendicular to the surface of HTNTs. At the same time, the dispersion capacity is also measurement by the fit of C 1s XPS peak at various BA loadings at first time.

Wang, Wei; Zhang, Jingwei; Huang, Huizhong; Wu, Zhishen; Zhang, Zhijun

2007-04-01

159

Electric field-controlled benzoic acid and sulphanilamide delivery from poly(vinyl alcohol) hydrogel.  

PubMed

The controlled release of benzoic acid (3.31) and sulphanilamide (3.47) from poly(vinyl alcohol), PVA, hydrogels fabricated by solution casting at various cross-linking ratios, were investigated. The PVA hydrogels were characterized in terms of the degree of swelling, the molecular weight between cross-links, and the mesh size. The drug release experiment was carried out using a modified Franz diffusion cell, at a pH value of 5.5 and at temperature of 37C. The amount of drug release and the diffusion coefficients of the drugs from the PVA hydrogels increased with decreasing cross-linking ratio, as a larger mesh size was obtained with lower cross-linking ratios. With the application of an electric field, the amount of drug release and the diffusion coefficient increased monotonically with increasing electric field strength, since the resultant electrostatic force drove the ionic drugs from the PVA matrix. The drug size, matrix pore size, electrode polarity, and applied electric field were shown to be influential controlling factors for the drug release rate. PMID:23065453

Sittiwong, Jarinya; Niamlang, Sumonman; Paradee, Nophawan; Sirivat, Anuvat

2012-12-01

160

Degradation of mono-, di-, and trihalogenated benzoic acids by Pseudomonas aeruginosa JB2.  

PubMed

Pseudomonas aeruginosa JB2 was isolated from a polychlorinated biphenyl-contaminated soil by enrichment culture containing 2-chlorobenzoate as the sole carbon source. Strain JB2 was subsequently found also to grow on 3-chlorobenzoate, 2,3- and 2,5-dichlorobenzoates, 2,3,5-trichlorobenzoate, and a wide range of other mono- and dihalogenated benzoic acids. Cometabolism of 2,4-dichlorobenzoate was also observed. Chlorocatechols were the central intermediates of all chlorobenzoate catabolic pathways. Degradation of 2-chlorobenzoate was routed through 3-chlorocatechol, whereas 4-chlorocatechol was identified from the metabolism of both 2,3- and 2,5-dichlorobenzoate. The initial attack on chlorobenzoates was oxygen dependent and most likely mediated by dioxygenases. Although plasmids were not detected in strain JB2, spontaneous mutants were detected in 70% of glycerol-grown colonies. The mutants were all of the following phenotype: benzoate+, 3-chlorobenzoate+, 2-chlorobenzoate-, 2,3-dichlorobenzoate-, 2,5-dichlorobenzoate-. While chlorocatechols were oxidized by the mutants at wild-type levels, oxidation of 2-chloro- and 2,3- and 2,5-dichlorobenzoates was substantially diminished. These findings suggested that strain JB2 possessed, in addition to the benzoate dioxygenase, a halobenzoate dioxygenase that was necessary for the degradation of chlorobenzoates substituted in the ortho position. PMID:2128010

Hickey, W J; Focht, D D

1990-12-01

161

First-principles prediction of the effects of temperature and solvent selection on the dimerization of benzoic acid.  

PubMed

We introduce a procedure of quantum chemical calculations (B3P86/6-31G**) to study carboxylic acid dimerization and its correlation with temperature and properties of the solvent. Benzoic acid is chosen as a model system for studying dimerization via hydrogen bonding. Organic solvents are simulated using the self-consistent reaction field (SCRF) method with the polarized continuum model (PCM). The cyclic dimer is the most stable structure both in gas phase and solution. Dimer mono- and dihydrates could be found in the gas phase if acid molecules are in contact with water vapor. However, the formation of these hydrated conformers is very limited and cyclic dimer is the principal conformer to coexist with monomer acid in solution. Solvation of the cyclic dimer is more favorable compared to other complexes, partially due to the diminishing of hydrogen bonding capability and annihilation of dipole moments. Solvents have a strong effect on inducing dimer dissociation and this dependence is more pronounced at low dielectric constants. By accounting for selected terms in the total free energy of solvation, the solvation entropy could be incorporated to predict the dimer behavior at elevated temperatures. The temperature dependence of benzoic acid dimerization obtained by this technique is in good agreement with available experimental measurements, in which a tendency of dimer to dissociate is observed with increased temperatures. In addition, dimer breakup is more sensitive to temperature in low dielectric environments rather than in solvents with a higher dielectric constant. PMID:23256609

Pham, Hieu H; Taylor, Christopher D; Henson, Neil J

2013-01-24

162

Adsorption of benzoic acid, phthalic acid on gold substrates studied by surface-enhanced Raman scattering spectroscopy and density functional theory calculations  

NASA Astrophysics Data System (ADS)

Benzoic acid (BA) and phthalic acid (PTA) are the simplest aromatic carboxylic acids, and they can be regarded as typical model compounds in investigating the interaction of aromatic carboxylic acids with metal surfaces by use of SERS spectroscopy. In this work, we have investigated the structure and adsorption behavior of benzoic acid and phthalic acid on the gold surface with combination of SERS and DFT calculation methods. The experimental results show that both BA and PTA may be adsorbed on the Au surface with a bidentate bridging structure, namely, the carboxylate group(s) being bound to gold via two oxygen atoms in the carboxylate group(s). Comparison of the observed SERS and predicted spectra of the complexes of these two substances with Au atoms indicates that BA is favorable to adsorb on the gold surface with a vertical orientation rather than a flat one, and PTA could "stand up" on the Au surface as a slight tilt with a two-legged geometry, i.e. all four oxygen atoms in two carboxylate groups interact on the metal surface. Apart from that, we compare the discrepancy of SERS spectra between those two molecules, which could be taken as a potential analysis technique in food safety field.

Gao, Jiao; Hu, Yongjun; Li, Shaoxin; Zhang, Yanjiao; Chen, Xue

2013-03-01

163

Adsorption of benzoic acid, phthalic acid on gold substrates studied by surface-enhanced Raman scattering spectroscopy and density functional theory calculations.  

PubMed

Benzoic acid (BA) and phthalic acid (PTA) are the simplest aromatic carboxylic acids, and they can be regarded as typical model compounds in investigating the interaction of aromatic carboxylic acids with metal surfaces by use of SERS spectroscopy. In this work, we have investigated the structure and adsorption behavior of benzoic acid and phthalic acid on the gold surface with combination of SERS and DFT calculation methods. The experimental results show that both BA and PTA may be adsorbed on the Au surface with a bidentate bridging structure, namely, the carboxylate group(s) being bound to gold via two oxygen atoms in the carboxylate group(s). Comparison of the observed SERS and predicted spectra of the complexes of these two substances with Au atoms indicates that BA is favorable to adsorb on the gold surface with a vertical orientation rather than a flat one, and PTA could "stand up" on the Au surface as a slight tilt with a two-legged geometry, i.e. all four oxygen atoms in two carboxylate groups interact on the metal surface. Apart from that, we compare the discrepancy of SERS spectra between those two molecules, which could be taken as a potential analysis technique in food safety field. PMID:23261703

Gao, Jiao; Hu, Yongjun; Li, Shaoxin; Zhang, Yanjiao; Chen, Xue

2013-03-01

164

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

SciTech Connect

The long-day plant Lemna gibba G3 fails to flower under continuous light on NH/sub 4//sup +/-free 0.5 H medium. This inhibition is completely reversed by 10 ..mu..M salicyclic acid (SA) or 32 ..mu..M benzoic acid (BA). By contrast, p-hydroxybenzoic acid (p-OH-BA) has virtually no effect on flowering at levels as high as 320 ..mu..M. Uptake rates for the three compounds are comparable. Competition studies using /sup 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 /sup 14/C-SA uptake. Both the effectiveness of SA for inducing flowering and the uptake of /sup 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 /sup 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.

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

1986-04-01

165

Effects of Benzoic Acid and Dietary Calcium:Phosphorus Ratio on Performance and Mineral Metabolism of Weanling Pigs  

PubMed Central

In a 22 factorial experiment the hypotheses tested were that the metabolic acid load caused by benzoic acid (BA) added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or 0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered. Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10). Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its implementation under practical feeding conditions.

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

2014-01-01

166

Voltammetric studies of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid as a novel prodrug of 5-aminosalicylic acid.  

PubMed

The electrochemical properties of a colon-targeted prodrug of 5-aminosalicylic acid (5-ASA), 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid (SPSA), were investigated in aqueous solutions at glassy carbon electrodes using cyclic voltammetry and controlled potential electrolysis. The influence of the pH and experimental time domain on the reaction pathway has been studied. The electrochemical reduction of SPSA is identified as an ECE process always leading to the cleavage of azo bond. In an acidic media SPSA is reduced in a 4e(-)/4H(+) process yielding 5-ASA and sulfanilic acid. In neutral and weakly basic media SPSA is reduced in 2e(-)/2H(+) process resulting in the hydrazo intermediate that is stable enough to enable its reoxidation back to SPSA in the time scale of the cyclic voltammetry. PMID:11600311

Nigovi?, B; Mandi?, Z; Simuni?, B; Fistri?, I

2001-12-01

167

Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column.  

PubMed

The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops. PMID:16165338

Satnsk, Dalibor; Huclov, Jitka; Ferreira, Raquel L C; Montenegro, Maria Conceio B S M; Solich, Petr

2006-02-13

168

Application of the Hammett free energy relationship to muonium addition reactions with benzoic acid derivatives in aqueous solutions  

NASA Astrophysics Data System (ADS)

Kinetic isotope effects and Hammett reaction parameters ? have been determined for the interaction of muonium atoms (Mu) in water with substituted benzoic acids as reactive solutes. The ? parameter for muonium has a value of +0.27 0.05, which indicates a weakly nucleophilic attack by Mu to give free-radical intermediates. In contrast, the analogous H-atom reactions show slight electrophilic character and are slower than Mu by more than the mean thermal velocity effect. These results were obtained in "muon spin rotation" studies.

Stadlbauer, J. M.; Miyake, Y.; Ng, B. W.; Phillips, E. C.; Walker, D. C.

169

Quantum proton transfer and interconversion in the benzoic acid crystal: vibrational spectra, mechanism and theory  

NASA Astrophysics Data System (ADS)

The infrared and Raman spectra of powdered crystals at various temperatures from liquid helium to 300 K of fully hydrogenated benzoic acid (BA-h 6), ring deuterated (BA-d 5h) and OD (BA-h 5d) analogues are presented. In the frequency range corresponding to internal modes there is no evidence for thermal equilibrium due to tautomerisation. Noticeable temperature effects are observed in Raman for a band at 80 cm -1. As the temperature increases, the band intensity decreases according to an Arrhenius law with activation energy of (546) cm-1. It is concluded that interconversion of protons occurs upon specific excitation of the lattice mode observed at ? R '=55 cm-1. In the ground state all dimers have the same configuration throughout the crystal, whilst the excited phonon state is a coherent superposition of the two tautomers. An isotopic mixture containing 5% of OH and 95% of OD residues demonstrates the absence of dynamical correlation between protons. The OH (OD) stretching band profiles in the infrared are decomposed into two broad components whose shapes are rationalised with the strong coupling scheme for the ? OH and ? O⋯ O coordinates. The splitting is attributed to proton tunnelling in the n=2 and 3 states of a quasi-symmetric double minimum potential. This assignment is confirmed with the 0?1 transition (the splitting of the ground state) observed with the inelastic neutron scattering technique at ? 01=172 cm-1 for BA-d 5h. The potential governing the quantum transfer dynamics of a single proton is thus totally determined from experimental data. The potential barrier is 5000 cm -1 and semiclassical jumping over the top is negligible. We propose a theory based on uncorrelated transfer of protons via thermally activated tunnelling to account for the interconversion dynamics. The analytical function for the interconversion rate versus temperature accounts for NMR T 1 and quasi-elastic neutron scattering (QENS) measurements. Both the potential function for protons and the coherent superposition of tautomers survive at room temperature.

Fillaux, F.; Limage, M. H.; Romain, F.

2002-02-01

170

Simultaneous analysis of glycyrrhizin, paeoniflorin, quercetin, ferulic acid, liquiritin, formononetin, benzoic acid and isoliquiritigenin in the Chinese proprietary medicine Xiao Yao Wan by HPLC.  

PubMed

A high performance liquid chromatography coupled with photodiode-array detection method was developed for simultaneous determination of glycyrrhizin, paeoniflorin, benzoic acid, quercetin, ferulic acid, formononetin, liquiritin and isoliquiritigenin in the Chinese proprietary medicine "Xiao Yao Wan" (XYW). The analysis was performed by reverse phase gradient elution, using an aqueous mobile phase (containing 0.1% phosphoric acid) modified by acetonitrile and detection made simultaneously at four wavelengths. The method was validated for accuracy, precision and limits of detection and quantification. Ten batches of XYW obtained from different pharmaceutical companies were analyzed and found to contain different amounts of the eight bioactive markers. This method could be used for quality assessment of this herbal medicine. PMID:17709224

Xie, Junbo; Wang, Wenquan; Zhang, Yanqing; Bai, Yin; Yang, Quan

2007-11-01

171

Human sialidase inhibitors: design, synthesis, and biological evaluation of 4-acetamido-5-acylamido-2-fluoro benzoic acids.  

PubMed

Recent advances in the sialidase biology have clarified the role of human sialidases (NEU 1 to NEU4) in the development of various disease states such as cancer, diabetes and arteriosclerosis. Isoform selective human sialidase inhibitors could be a therapeutic tool or molecular probes for the exploration of the specific functions of human sialidases. In the present study, de novo design based virtual screening was performed to find a new class of human sialidase inhibitors using the experimental crystal structure of NEU2 isoform. A few of nitro benzene and fluoro benzoic acid were identified and a series of 4-acetamido-5-acylamido-2-fluoro benzoic acids were synthesized and, the inhibitory activity of all these compounds against all human sialidase enzymes was evaluated. All these compounds were found to have a poor inhibitory activity and only NEU2 showed more sensitivity to this series of compounds as compared to other isoforms. Molecular docking was performed to gain insight regarding the binding mode of these inhibitors and thereby provided valuable information for our study on the design of selective human sialidase inhibitors further. PMID:19450982

Magesh, Sadagopan; Savita, Vats; Moriya, Setsuko; Suzuki, Tohru; Miyagi, Taeko; Ishida, Hideharu; Kiso, Makoto

2009-07-01

172

Effect of 2-Hydroxy-4-methoxy Benzoic Acid Isolated from Hemidesmus indicus on Erythrocyte Membrane Bound Enzymes and Antioxidant Status in Streptozotocin-induced Diabetic Rats.  

PubMed

In the present study, the effect of 2-hydroxy-4-methoxy benzoic acid isolated from roots of Hemisdesmus indicus on the erythrocyte membrane bound enzymes and antioxidant status in streptozotocin-induced diabetic rats was investigated. The streptozotocin-induced diabetic rats were treated with 2-hydroxy-4-methoxy benzoic acid (500 ?g/kg/day) for 7 weeks by oral intubation and compared with glibenclamide, a standard hypoglycemic agent (100 mg/kg). The erythrocyte membrane was isolated and the activity of Na(+)/K(+)-dependent ATPases, Ca(2+)-ATPases, Mg(2+)-ATPases were determined. Superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, vitamins C, vitamin E, plasma reduced glutathione and erythrocyte glutathione, reduced glutathione content in the tissues was also assayed. Administration of 2-hydroxy-4-methoxy benzoic acid to diabetic rats significantly (F>0.05 and P<0.001) elevated the activity of total ATPases, Na(+)/k(+) ATPase, Mg(2+) ATPase and Ca(2+) ATPase to near normal level. The activities of catalase, superoxide dismutase and glutathione peroxidase and glutathione-S-transferase in erythrocytes were decreased significantly (F>0.05; P<0.001) in diabetic rats. Diabetic rats treated with 2-hydroxy-4-methoxy benzoic acid showed a significant (F>0.05; <0.001) increase in the enzymic antioxidants in erythrocytes. The elevated levels of vitamin E and low level of vitamin C and glutathione level in plasma and erythrocytes were observed in diabetic rats when compared to control rats and were restored significantly (F>0.05; P<0.001) after the administration of 2-hydroxy-4-methoxy benzoic acid. This study concludes administration of 2-hydroxy-4-methoxy benzoic acid supports the restoration of antioxidant defence, reduces the free radial production, lipid peroxidation and the glycosylation of haemoglobin in diabetic rats. PMID:23716880

Gayathri, M; Kannabiran, K

2012-09-01

173

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

PubMed Central

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 ?-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 ?-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.

2012-01-01

174

Photolytic degradation of chlorophenols from industrial wastewaters by organic oxidants peroxy acetic acid, para nitro benzoic acid and methyl ethyl ketone peroxide: identification of reaction products.  

PubMed

In this investigation, chlorophenol (CP) containing industrial wastewater was remediated by ultraviolet irradiation in conjunction with organic oxidants, peroxy acetic acid (PAA); para nitro benzoic acid (PNBA); and methyl ethyl ketone peroxide (MEKP). CP mineralization was studied with regard to chemical oxygen demand (COD) and chloride ion release under identical test conditions. COD depletion to the extent of 81% by PAA, 66% by PNBA, and 67% by MEKP was noted along with an upwardly mobile trend of chloride ion release upon irradiation of samples at 254 nm. A 90-99% decrease in CP concentration (as per high pressure liquid chromatography (HPLC) analysis) was achieved with an additional 15.0 ml of organic oxidant in all cases. Gas chromatography high resolution mass spectroscopy (GC-HRMS) results also indicated the formation of such reaction products as are free from chlorine substitutions. This treatment also leads to total decolorization of the collected samples. PMID:24647192

Sharma, Swati; Mukhopadhyay, Mausumi; Murthy, Zagabathuni Venkata Panchakshari

2014-01-01

175

A complex of poly(4-vinylpyridine) and tolane based hemi-phasmid benzoic acid: towards luminescent supramolecular side-chain liquid crystalline polymers.  

PubMed

A supramolecular side-chain liquid crystalline (LC) polymer P4VP()x was prepared using poly(4-vinylpyridine) and a tolane based hemi-phasmid benzoic acid. P4VP()x exhibits good processability, forming smectic and hexagonal columnar LC phases at different compositions. Its photoluminescence properties depend on the LC structures. PMID:24942345

Wang, Shao-Jie; Zhao, Rui-Ying; Yang, Shuang; Yu, Zhen-Qiang; Chen, Er-Qiang

2014-07-01

176

X-ray photoelectron spectroscopy study of para-substituted benzoic acids chemisorbed to aluminum oxide thin films  

SciTech Connect

A series of para-substituted, halogenated (F, Cl, Br, and I) benzoic acid monolayers were prepared on the native oxide of aluminum surfaces by solution self-assembly and spin-coating techniques. The monolayers were characterized by x-ray photoelectron spectroscopy (XPS) and water contact angles. Several general trends are apparent. First, the polarity of the solvent is critical to monolayer formation. Protic polar solvents produced low coverage monolayers; in contrast, nonpolar solvents produced higher coverage monolayers. Second, solution deposition yields a higher surface coverage than spin coating. Third, the thickness of the monolayers determined from XPS suggests the plane of the aromatic ring is perpendicular to the surface with the carboxylate functional group most likely binding in a bidentate chelating geometry. Fourth, the saturation coverage (?2.7 10{sup 14} molecules cm{sup ?2}) is independent of the para-substituent.

Kreil, Justin; Ellingsworth, Edward; Szulczewski, Greg [Department of Chemistry, The University of Alabama, Shelby Hall, 250 Hackberry Lane, Tuscaloosa, Alabama 35487 (United States)] [Department of Chemistry, The University of Alabama, Shelby Hall, 250 Hackberry Lane, Tuscaloosa, Alabama 35487 (United States)

2013-11-15

177

o-Alkylselenenylated benzoic acid accesses several sites in serum albumin according to fluorescence studies, Raman spectroscopy and theoretical simulations.  

PubMed

In the circulatory system, serum albumin (SA) is an important transporter of the majority of molecules with biological activity. We focused the current study on the anti-inflammatory compound, o-alkylselenenylated benzoic acid (ALKSEBEA), to determine its ability to access SA. Herein, we employed experimental procedures (fluorescence studies, Raman spectroscopy) and docking study on SA obtained from the Protein Data Bank and key conformers obtained from molecular dynamics simulations. The results show that ALKSEBEA accesses SA using a cooperative behavior according to fluorescence studies. In addition, the Raman results indicate that the ligand binding affects the backbone constituents. These results were confirmed by docking simulations tested on several SA conformers, which showed that ALKSEBEA bound on several sites on SA via ?-? or ?-cation interactions and that the ligand reaches other binding sites, where aromatic and basic residues as well as the backbone residues are involved. PMID:22973844

Martinez-Ramos, Federico; Fonseca-Sabater, Yadira; Soriano-Ursa, Marvin A; Torres, Eduardo; Rosales-Hernndez, Martha C; Trujillo-Ferrara, Jos G; Tolentino-Lopez, Luis E; Ilizaliturri-Flores, Ian; Correa-Basurto, Jos

2013-06-01

178

Studies on the reaction mechanism in the irradiation of solutions containing ferrous ions, benzoic acid and xylenol orange  

NASA Astrophysics Data System (ADS)

In this paper we have investigated the radiation mechanism of the "FBX" system. By using the competitive kinetics of benzoic acid, we found that rate constant of the reaction OH radical with xylenol orange is 8.4x10 9 dm 3mol -1s -1. In both the "FB" and "FBX" systems, the yields of ferrous ions oxidized to ferric ions by 60Co ?-rays is represented by G FB =G H2O2+2G H+11(G H 2O 2+G OH+G H) and G FBX=G H 2O 2+2G H+(G H 2O 2G OH+G H) {9K 5[C 6H 5COOH]+K 9[XO] }/{K 5[C 6H 5COOH]+K 9[XO]' } respectively.

Jia-Shan, Zhang; Zhi-Li, Wu; Xin-Wei, Chen

179

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

NASA Astrophysics Data System (ADS)

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

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

2009-10-01

180

Substrate effects on the surface-enhanced Raman spectrum of benzoic acid adsorbed on silver oblate microparticles  

SciTech Connect

The effects of the local dielectric environment on the surface-enhanced Raman-scattering enhancement factor of benzoic acid adsorbed on silver oblate spheroids are studied experimentally and modeled theoretically. Silver-island films were annealed to produce spheroidal-shaped particles which exhibit well resolved resonances in absorption spectra. These resonances are shifted in different amounts by the depolarizing interaction with the substrate. An additional dielectric film has been deposited between the particles and substrate in order to measure the effects of proximity on the surface-enhanced Raman signal. Experimental observations on germanium and silicon are presented and found to be in agreement with calculations involving only the surface-plasmon excitation on the particles.

Goudonnet, J.P.; Bijeon, J.L.; Warmack, R.J.; Ferrell, T.L. (Health and Safety Research Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (US))

1991-02-15

181

Crystal structure of complexes of bivalent Co, Ni, and Cd with anions of benzoic and 2-(acetylamino)-5-nitrobenzoic acids  

NASA Astrophysics Data System (ADS)

The structure of three complexes of bivalent metals (cobalt, nickel, and cadmium) with anions of benzoic (H L 1) and 2-(acetylamino)-5-nitrobenzoic (H L 2) acids, namely, [Co{2/1} (H2O)2(?-C4H4N2)] n ( I), [NiL2(H2O)5]L2 2H2O ( II), and [Cd(?- L 2)2(H2O)2] n 2 nH2O ( III), is determined. In chainlike structure I, cobalt atoms are connected by bridging pyrazine molecules; structure II contains isolated complexes. In structure III, centrosymmetric (CdOCO)2 cycles and polymeric ribbons are formed due to the coordination of the carboxylate group of the L 2 ligand to two cadmium atoms.

Rzaeva, M. F.; Askerov, R. K.; Movsumov, E. M.; Sergienko, V. S.; Ilyukhin, A. B.

2012-03-01

182

2-Amino-benzoic acid-4-[2-(pyridin-4-yl)eth-yl]pyridine (2/1).  

PubMed

The asymmetric unit of the title co-crystal, C12H12N22C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-yl)eth-yl]pyridine mol-ecule and a 2-amino-benzoic acid mol-ecule in a general position. The acid has a small twist between the carb-oxy-lic acid residue and the ring [dihedral angle = 7.13?(6)] despite the presence of an intra-molecular N-H?O(carbon-yl) hydrogen bond. Three-mol-ecule aggregates are formed via O-H?N(pyrid-yl) hydrogen bonds, and these are connected into supra-molecular layers in the bc plane by N-H?O(carbon-yl) hydrogen bonds and ?-? inter-actions between pyridine and benzene rings [inter-centroid distance = 3.6332?(9)?]. Layers are connected along the a axis by weak ?-? inter-actions between benzene rings [3.9577?(10)?]. PMID:24454067

Arman, Hadi D; Tiekink, Edward R T

2013-10-01

183

Free and Conjugated Benzoic Acid in Tobacco Plants and Cell Cultures. Induced Accumulation upon Elicitation of Defense Responses and Role as Salicylic Acid Precursors1  

PubMed Central

Salicylic acid (SA) is a key endogenous component of local and systemic disease resistance in plants. In this study, we investigated the role of benzoic acid (BA) as precursor of SA biosynthesis in tobacco (Nicotiana tabacum cv Samsun NN) plants undergoing a hypersensitive response following infection with tobacco mosaic virus or in tobacco cell suspensions elicited with ?-megaspermin, an elicitor from Phytophthora megasperma. We found a small pool of conjugated BA in healthy leaves and untreated cell suspensions of tobacco, whereas free BA levels were barely detectable. Infection of plants with tobacco mosaic virus or elicitation of cells led to a rapid de novo synthesis and accumulation of conjugated BA, whereas free BA was weakly induced. In presence of diphenylene iodonium, an inhibitor of superoxide anion formation, SA accumulation was abolished in elicited cells and much higher BA levels were concomitantly induced, mainly as a conjugated form. Furthermore, piperonylic acid, an inhibitor of cinnamate-4-hydroxylase was used as a powerful tool to redirect the metabolic flow from the main phenylpropanoid pathway into the SA biosynthetic branch. Under these conditions, in vivo labeling and radioisotope dilution experiments with [14C]trans-cinnamic acid as precursor clearly indicated that the free form of BA produced in elicited tobacco cells is not the major precursor of SA biosynthesis. The main conjugated form of BA accumulating after elicitation of tobacco cells was identified for the first time as benzoyl-glucose. Our data point to the likely role of conjugated forms of BA in SA biosynthesis.

Chong, Julie; Pierrel, Marie-Agnes; Atanassova, Rossitza; Werck-Reichhart, Daniele; Fritig, Bernard; Saindrenan, Patrick

2001-01-01

184

syn and anti conformations in 2-hydroxy-5-[(E)-(4-nitrophenyl)diazenyl]benzoic acid and two related salts.  

PubMed

The crystal structures of 2-hydroxy-5-[(E)-(4-nitrophenyl)diazenyl]benzoic acid, C13H9N3O5, (I), ammonium 2-hydroxy-5-[(E)-phenyldiazenyl]benzoate, NH4(+)C13H9N2O3(-), (II), and sodium 2-hydroxy-5-[(E)-(4-nitrophenyl)diazenyl]benzoate trihydrate, Na(+)C13H8N3O5(-)3H2O, (III), have been determined using single-crystal X-ray diffraction. In (I) and (III), the phenyldiazenyl and carboxylic acid/carboxylate groups are in an anti orientation with respect to each other, which is in accord with the results of density functional theory (DFT) calculations, whereas in (II), the anion adopts a syn conformation. In (I), molecules form slanted stacks along the [100] direction. In (II), anions form bilayers parallel to (010), the inner part of the bilayers being formed by the benzene rings, with the -OH and -COO(-) substituents on the bilayer surface. The NH4(+) cations in (II) are located between the bilayers and are engaged in numerous N-H...O hydrogen bonds. In (III), anions form layers parallel to (001). Both Na(+) cations have a distorted octahedral environment, with four octahedra edge-shared by bridging water O atoms, forming [Na4(H2O)12](4+) units. PMID:24816020

Yatsenko, Alexandr V; Paseshnichenko, Ksenia A

2014-05-01

185

Synthesis of new 2-([(phenoxy or phenyl)acetyl]amino)benzoic acid derivatives as 3 alpha-hydroxysteroid dehydrogenase inhibitors and potential antiinflammatory agents.  

PubMed

A number of 2-([(phenoxy or phenyl)acetyl]amino)benzoic acid derivatives were prepared in about 50% yield from (phenoxy or phenyl)acetyl chloride and anthranilic acid derivatives. All the compounds were tested as in vitro inhibitors of 3 alpha-hydroxysteroid dehydrogenase, since enzyme inhibition predicts potential antiinflammatory activity in vivo. The most active compounds 3 l, m, s are about 3.5 times more active than acetylsalicylic acid (ASA). Activity is influenced by electronic as well as steric effects. PMID:8554459

Daidone, G; Plescia, S; Bajardi, M L; Schillaci, D

1995-10-01

186

Degradation of chloro- and methyl-substituted benzoic acids by a genetically modified microorganism  

SciTech Connect

Degradation of 3-chlorobenzoic acid (3CB), 4-chlorobenzoic acid (4CB), and 4-methylbenzoic acid (4MB) as single substrates (carbon sources) and as a substrate mixture were studied in batch and continuous culture using the genetically modified microorganism Pseudomonas sp. B13 FR1 SN45P. The strain was able to mineralize the single compounds as well as the substrate mixture completely. Conversion of the three compounds in the substrate mixture proceeded simultaneously. Maximum specific substrate conversion rates were calculated to be 0.9 g g{sup {minus}1} h{sup {minus}1} for 3 CB and 4CB and 1.1 g g{sup {minus}1} h{sup {minus}1} for 4MB. Mass balances indicated the transient accumulation of pathway intermediates during batch cultivations. Hence, the rate limiting step in the degradative pathway is not the initial microbial attack of the original substrate or its transport through the cell membrane. Degradation rates on 3CB were comparable to those of the parent strain Pseudomonas sp. B13. The stability of the degradation pathways of strain Pseudomonas sp. B13 FR1 SN45P could be demonstrated in a continuous cultivation over 3.5 months (734 generation times) on 3CB, 4MB, and 4CB, which were used a single carbon sources one after the other.

Mueller, R.; Deckwer, W.D.; Hecht, V. [Gesellschaft fuer Biotechnologische Forschung mbH, Braunschweig (Germany)

1996-09-05

187

Thiosemicarbazones of formyl benzoic acids as novel potent inhibitors of estrone sulfatase.  

PubMed

Thiosemicarbazones of the microbial metabolite madurahydroxylactone, a polysubstituted benzo[a]naphthacenequinone, have been previously reported by us as potent nonsteroidal inhibitors of the enzyme estrone sulfatase (cyclohexylthiosemicarbazone 1, IC50 0.46 microM). The active pharmacophore of 1 has now been identified to be 2-formyl-6-hydroxybenzoic acid cyclohexylthiosemicarbazone (25, IC50 4.2 microM). The active partial structure was derivatized in the search for novel agents against hormone-dependent breast cancer. Further substantial increases in activity were achieved by reversal of functional groups leading to the cyclohexylthiosemicarbazones of 5-formylsalicylic acid (35, IC50 0.05 microM) and 3-formylsalicylic acid (34, IC50 0.15 microM) as the most potent analogues identified to date. Both compounds were shown to be noncompetitive inhibitors of estrone sulfatase with Ki values of 0.13 microM and 0.12 microM, respectively. The compounds showed low acute toxicity in the hen's fertile egg screening test. PMID:17580843

Jtten, Peter; Schumann, Winfried; Hrtl, Albert; Dahse, Hans-Martin; Grfe, Udo

2007-07-26

188

Proton tunnelling in the hydrogen bonds of the benzoic Acid dimer: (18)o substitution and isotope effects of the heavy atom framework.  

PubMed

Field-cycling (1)H NMR relaxometry has been used to measure the rate of concerted double proton transfer in the hydrogen bonds of (16)O and (18)O isotopologues of benzoic acid dimers. The experiments have been conducted in the solid state at low temperature 13.3 ? T ? 80 K where the dynamics are dominated by incoherent proton tunnelling. The low temperature tunnelling rate in the (16)O isotopologue is observed to be approximately 15% faster than in the (18)O isotopologue. The difference is attributed to an isotope effect of the heavy atom framework of the benzoic acid dimer resulting from displacements of the oxygen atoms that accompany the proton transfer. Sources of systematic uncertainty have been minimized in the design of the experimental protocols and the experiments are critically appraised in formally assigning the measured differences to an effect of mass on the tunnelling dynamics. PMID:24428637

Frantsuzov, I; Johnson, M R; Trommsdorff, H P; Horsewill, A J

2014-07-17

189

Adsorption of o-cresol and benzoic acid in an adsorber packed with an ion-exchange resin: A comparative study of diffusional models  

SciTech Connect

Both solid- and pore-diffusion models were employed to simulate the adsorption of o-cresol and benzoic acid in a fixed-bed adsorber packed with an anion-exchange resin. The equilibrium adsorption data were modeled by a Langmuir isotherm. When the shape of the adsorption isotherm was approximately linear (as in the case of o-cresol), both models agreed well with the experimental break-through data, and they could be effectively applied to predict the breakthrough curve of longer columns. For a favorable adsorption isotherm (say, benzoic acid), however, better results were obtained by using the solid-diffusion model. In addition to the shape of the adsorption isotherm, several factors, such as the type of adsorbent, modeling of equilibrium data, computation efficiency, and concentration dependence of the intraparticle diffusivity, should also be taken into account for selecting a suitable diffusion model.

Run-Tun Huang; Teh-Liang Chen; Hung-Shan Weng [National Cheng Kung Univ., Taiwan (China)

1994-10-01

190

2-[(2-Acet-oxy-benzo-yl)-oxy]benzoic acid.  

PubMed

The title compound, C(16)H(12)O(6), is a common impurity of ortho-acetyl-salicylic acid (aspirin). The benzene rings form a dihedral angle of 81.9?(1) while the acetyl and carboxyl groups form dihedral angles of 74.0?(1) and 26.4?(2), respectively, with the benzene rings to which they are bound. In the crystal, mol-ecules are linked by pairs of O-H?O hydrogen bonds between the carboxyl groups, forming inversion dimers. PMID:22798785

Solanko, Katarzyna A; Bond, Andrew D

2012-07-01

191

Stabilization of two smallest possible diastereomeric ?-hairpins in a water soluble tetrapeptide containing non-coded ?-amino isobutyric acid (Aib) and m-amino benzoic acid  

NASA Astrophysics Data System (ADS)

Single crystal X-ray diffraction study reveals that the water soluble tetrapeptide H 2N-Ile-Aib-Leu- m-ABA-CO 2H, containing non-coded Aib (?-amino isobutyric acid) and m-ABA ( meta-amino benzoic acid), crystallizes with two smallest possible diastereomeric ?-hairpin molecules in the asymmetric unit. Although in both of the molecules the chiralities at Ile(1) and Leu(3) are S, a conformational reversal in the back bone chain is observed to produce the ?-hairpins with ?-turn conformations of type II and II'. Interestingly Aib which is known to adopt helical conformation, adopts unusual semi-extended conformation with ?: -49.5(5), ?: 135.2(5) in type II and ?: 50.6(6), ?: -137.0(4) in type II' for occupying the i + 1 position of the ?-turns. The two hairpin molecules are further interlocked through intermolecular hydrogen bonds and electrostatic interactions between - CO2- and - +NH 3 groups to form dimeric supramolecular ?-hairpin aggregate in the crystal state. The CD measurement and 2D NMR study of the peptide in aqueous medium support the existence of ?-hairpin structure in water.

Dutt, Anita; Dutta, Arpita; Kar, Sudeshna; Koley, Pradyot; Drew, Michael G. B.; Pramanik, Animesh

2009-06-01

192

Spectroscopic and atomic force microscopy characterization of the electrografting of 3,5-bis(4-diazophenoxy)benzoic acid on gold surfaces.  

PubMed

The synthesis of a bipodal diazonium salt, 3,5-bis(4-diazophenoxy)benzoic acid, and the study of its electrochemical deposition on gold surfaces is presented. The presence of the organic layer on the gold surface was characterized using atomic force microscopy and X-ray photoelectron spectroscopy, demonstrating the presence of phenyl groups, indicative of the grafted layer as well as the formation of multilayers, dependent on the electrografting conditions. PMID:22960009

Civit, Laia; El-Zubir, Osama; Fragoso, Alex; O'Sullivan, Ciara K

2013-03-15

193

Viper venom-induced inflammation and inhibition of free radical formation by pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from anantamul ( Hemidesmus indicus R.Br) root extract  

Microsoft Academic Search

The present investigation explored the possible venom neutralizing effect of a pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from the methanolic root extract of Hemidesmus indicus R.Rr. 2-OH-4-MeO benzoic acid possessed potent anti-inflammatory, antipyretic and antioxidant properties. The compound effectively neutralized inflammation induced by Vipera russelli venom in male albino mice and reduced cotton pellet-induced granuloma in rats. The

M. I. Alam; A. Gomes

1998-01-01

194

Purification and Characterization of S-Adenosyl- l -methionine:Benzoic Acid Carboxyl Methyltransferase, the Enzyme Responsible for Biosynthesis of the Volatile Ester Methyl Benzoate in Flowers of Antirrhinum majus  

Microsoft Academic Search

S-Adenosyl-l-methionine:benzoic acid carboxyl methyltransferase (BAMT) catalyzes the transfer of the methyl group of S-adenosyl-l-methionine (SAM) to the carboxyl group of benzoic acid to make the volatile ester methyl benzoate, one of the most abundant scent compounds of snapdragon, Antirrhinum majus. The enzyme was purified from upper and lower petal lobes of 5- to 10-day-old snapdragon flowers using DE53 anion exchange,

Lisa M. Murfitt; Natalia Kolosova; Craig J. Mann; Natalia Dudareva

2000-01-01

195

Effect of MN (III) tetrakis (4-benzoic acid) porphyrin by photodynamically generated free radicals on SODs keratinocytes.  

PubMed

Superoxide, a reactive form of oxygen, can be produced in vivo either in normal and under pathophysiologic conditions or by photosensitizing chemicals, as during photodynamic treatment. Photodynamic therapies (PDT), widely adopted in Dermatology and Oncology, are known to generate reactive oxygen species (ROS) and may contribute to structural alterations and oxidatively generated modifications of cellular antioxidants. We hypothesized that over-production of free radicals would decrease the enzymatic activities of endogenous cellular antioxidants. To test this hypothesis, keratinocytes were treated with the photosensitizer Photofrin plus visible light to produce free radicals and CuZnSOD and MnSOD activities were measured. Photodynamic treatment of keratinocytes increases malonylaldehyde production, nitrotyrosine staining and superoxide production. The enzymatic activities of CuZnSOD and MnSOD were significantly decreased after Photofrin plus visible light treatment. Our results suggest that the main cellular antioxidant system can be inactivated by photodynamically generated ROS. Pretreatment of keratinocytes with free radicals scavenger such as Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP) was able to restore the endogenous antioxidant system activities, inhibiting the MDA formation, nitrotyrosine staining and superoxide formation. Antioxidant therapy could therefore be a useful tool in protecting healthy epidermal cells against common side effects induced by antitumor targeted therapies. PMID:24152829

Nistico, S; Ventrice, D; Dagostino, C; Lauro, F; Ilari, S; Gliozzi, M; Colica, C; Musolino, V; Carresi, C; Strongoli, M C; Vecchio, I; Rizzo, M; Mollace, V; Muscoli, C

2013-01-01

196

Structural change from homogenous structure to staging in benzoic acid intercalated LDH: experimental and molecular dynamics simulation insights.  

PubMed

The intercalation the of 4,4'-oxybis(benzoic acid) anion (OBA(2-)) into MgAl-layered double hydroxide (LDH) was carried out in formamide, and the structural change of the nanocomposites from homogenous to staging was investigated through in situ XRD, FT-IR, TG-DSC, SEM and molecular dynamics (MD) simulations. In both formamide and water, the nanocomposites had a homogenous structure with a basal spacing of ?1.7 nm, showing the configuration of OBA(2-) was vertical to the LDH layers; however, with a decrease in water content after drying, the structure changed to a staging with a basal spacing of 2.62 nm. This resulted from the 1.72 nm phase and another one of 0.85 nm, which was produced by the configuration of OBA(2-) horizontal to the LDH layers. MD simulations revealed that the LDH layers distorted surrounding OBA(2-), and the deformation became more severe with decreasing water content in the interlayer, leading to the staging formation. The simulated XRD pattern confirmed that the staging observed in the experimental pattern was of the Daumas-Hrold type. PMID:22635008

Zhang, Yanru; Tan, Hongwei; Zhao, Jing-xiang; Li, Xinxin; Ma, Hui; Chen, Xiaoduan; Yang, Xiaojing

2012-07-01

197

Three-dimensional radiation dose measurements with Ferrous Benzoic Acid Xylenol Orange in Gelatin gel and optical absorption tomography  

NASA Astrophysics Data System (ADS)

The optical characteristics of a Ferrous Benzoic Acid Xylenol Orange in Gelatin (FBXG) gel have been studied over the wavelength range 300-700 nm as a function of radiation dose. The unirradiated gel exhibits a strong absorption peak at 440 nm; with increasing dose this peak starts to reduce in intensity while a new broad peak centred at 585 nm begins to appear. Using 60Co gamma rays the absorption coefficients for these two peaks were found to vary linearly with dose up to at least 30 Gy with slopes of -0.028 cm-1 Gy-1 (440 nm) and 0.069 cm-1 Gy-1 (585 nm). The pre- and post-irradiation stability was studied and absorbance changes of less than 1% per hour were observed over periods of a few days. The NMR response of FBXG gels was found to be marginally reduced compared to the standard Fricke dosemeter in gel form and the NMR technique is much less sensitive than the optical readout method. Tissue equivalent phantoms with dimensions of several centimetres can be constructed of FBXG gel and Optical Absorption Tomography (OAT) used to measure the three-dimensional dose distribution within them after exposure to radiation beams. The OAT technique is a much simpler and cheaper method of readout compared with Magnetic Resonance Imaging (MRI).

Bero, M. A.; Gilboy, W. B.; Glover, P. M.; Keddie, J. L.

1999-02-01

198

D-?-A dye system containing cyano-benzoic acid as anchoring group for dye-sensitized solar cells.  

PubMed

A D-?-A dye (KM-1) incorporating cyano-benzoic acid as a new acceptor/anchoring group has been synthesized for dye-sensitized solar cells (DSCs) with a high molar extinction coefficient of 66,700 M(-1) cm(-1) at 437 nm. Theoretical calculations show that the hydrogen bond between -CN and surface hydroxyl leads to the most stable configuration on the surface of TiO(2). In addition, the adsorption of the dye on TiO(2) follows a Brunauer-Emmett-Teller (BET) isotherm. Multilayer adsorption of KM-1 on TiO(2) seems to take place particularly at higher dye concentrations. DSC device using KM-1 reached a maximum incident photon-to-current conversion efficiency (IPCE) of 84%, with a solar to electric power conversion efficiency (PCE) of 3.3% at AM1.5 G illumination (100 mW cm(-2)). This new type of anchoring group paves a way to design new dyes that combine good visible light harvesting with strong binding to the metal oxide surface. PMID:21999751

Katono, Masataka; Bessho, Takeru; Meng, Sheng; Humphry-Baker, Robin; Rothenberger, Guido; Zakeeruddin, Shaik M; Kaxiras, Efthimios; Grtzel, Michael

2011-12-01

199

Solubility and partial molar volumes of naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene in supercritical carbon dioxide  

SciTech Connect

The effect of temperature, pressure, and supercritical fluid density on the retention and solubility in the mobile phase of solutes in supercritical fluid chromatography was investigated. New retention data for naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene were obtained as a function of pressure at different temperatures. Most of the data were taken near the critical region of the fluid phase where the anomalities such as enhanced solubility/selectivity and retrogate behavior are expected. These data were then used to compare two different approaches for modeling the pressure dependence of solute retention on the column. In these approaches, mobile-phase partial molar volumes of the solutes were determined either from bulk solubility data or from infinite-dilution fugacity coefficients. In both approaches, an integrated expression for the change of retention with pressure was utilized to explicitly reveal the nature of interactions between the stationary phase and the solute. The approach that utilizes the infinite-dilution fugacity coefficient predicts the pressure dependence of solute retention more accurately, especially for solutes that are substantially soluble in the mobile phase near the critical point of the mobile phase. Relationships between the pressure and temperature dependence of the solute solubility in the mobile phase and the retention of solutes on the column were also investigated.

Goenenc, Z.S.; Akman, U. [Univ. of South Florida, Tampa, FL (United States). Dept. of Chemical Engineering]|[Bogaziici Univ., Istanbul (Turkey). Dept. of Chemical Engineering; Sunol, A.K. [Univ. of South Florida, Tampa, FL (United States). Dept. of Chemical Engineering

1995-07-01

200

Protective effect of 2-hydroxy-4-methoxy benzoic acid on testosterone induced benign prostatic hyperplasia in Wister rats.  

PubMed

Oxidative stress is one of the major causative factors for development of benign prostatic hyperplasia (BPH). The aim of the present study is to evaluate the effect of 2-hydroxy-4-methoxy benzoic acid (HMBA), a potential antioxidant on testosterone induced BPH in rats. Male Wistar rats were divided into five groups (n=6), Group I--received saline, Group II--received testosterone (3mg/kg/s.c.), Group III-received testosterone+finasteride (5mg/kg/oral), Group IV and V received testosterone+HMBA (200 and 400 ?g/kg/i.p.), respectively, for 21 days. Animals were weighed before and after the study period. On 22nd day, animals were humanly killed by cervical dislocation. Prostates were excised and weighed, and used for biochemical and histological studies. As a result, testosterone treated rats showed increased prostate weight; prostatic index accompanied with depleted antioxidant enzymes levels, elevated lipid peroxides and total nitrite and associated histology disruption. HMBA treatment at 200 ?g/kg/i.p. and 400 ?g/kg/i.p. significantly restored (P<0.05) antioxidant enzyme levels, lipid peroxide and total nitrite when compared to disease control animals. It also ameliorated the testosterone induced histological changes. The present study suggests the protective role of HMBA on testosterone induced BPH by virtue of its antioxidant potential. PMID:23123055

Ali, Mohd Ismail; Kondreddi, Hari Durga Prasad; Veeresh, B

2013-01-01

201

C 1s Near Edge X-ray Absorption Fine Structure (NEXAFS) of substituted benzoic acids: a theoretical and experimental study  

SciTech Connect

Ab initio calculations are performed to explain the discrete transitions in experimental C 1s-NEXAFS (near edge X-ray absorption fine structure) spectra of various benzoic acid derivates. Transition energies and oscillator strengths of the contributing C 1s-{pi}* excitations are computed using the ADC(2) (second-order algebraic-diagrammatic construction) method. This method is demonstrated to be well suited for the finite electronic systems represented by these simple organic acids. There is good agreement between experiment and theory reproducing all the relevant spectral features. Some transitions can only be assigned based on a theoretical foundation. Remaining discrepancies between experimental and computed spectra are discussed.

Baldea,I.; Schimmelpfennig, B.; Plaschke, M.; Rothe, J.; Schirmer, J.; Trofimov, A.; Fanghaenel, T.

2007-01-01

202

Excited state intramolecular proton transfer and dual emission of the cyclic homo- and heterodimers of 2-hydroxy and 2,6-dihydroxy benzoic acids  

NASA Astrophysics Data System (ADS)

The fluorescence and excitation spectra of homo- and heterodimers formed by salicylic and 2,6-dihydroxy benzoic acids (SA and DHBA respectively) with various carboxylic acids were obtained in the crystalline state, liquid and frozen glassy solutions within the temperature range 300-90 K. In all the cases, dual emission has been found with the low frequency band attributed to the excited state with intramolecular proton transfer (ESIPT) and the high frequency one to a state without ESIPT. The relative intensities of these bands depend strongly on the temperature, excitation wavelength and the pK a value of the second acid molecule involved in a cyclic dimer. The dual emission of molecules like methyl salicylate is conventionally explained in terms of the ground state tautomeric equilibrium with the OH ⋯ OH intramolecularly hydrogen bonded isomer incapable of ESIPT. Since in the case of 2,6-dihydroxy benzoic acid the only stable isomer with two hydrogen bonds can exist, this explanation seems to be at least insufficient. Other explanations of the dual emission origin are discussed. An attempt is made to explain the available experimental data using the hypothesis involving double well potential surface of the cyclic dimer in the excited state. In the framework of this hypothesis, the barrier between two wells emerges from the reorganization of the whole hydrogen bonded system of a dimer.

Denisov, G. S.; Golubev, N. S.; Schreiber, V. M.; Shajakhmedov, Sh. S.; Shurukhina, A. V.

1996-07-01

203

[Determination of intracellular pH by the distribution of benzoic acid in S. cerevisiae. Amino acid transport and proton gradient].  

PubMed

The internal pH (pHi) of Saccharomyces cerevisiae, wild type strain and its mutant rho- has been measured by the intra-extracellular distribution of 14C-benzoic acid. The values of pHi (external pH 4.5) change with the yeast strain and depend on the cellular metabolic conditions. The values of pHi and proton gradient in the wild type yeast are higher in energized than in starved cells: in energized cells pHi, 6.15 to 6.40, delta pH 1.65 to 1.90 or -97 to -112 mV; starved cells pH 5.90, delta pH 1.40 or -82 mV. In the rho- mutant, the values are lower than in the wild type yeast, in the same metabolic conditions. Energized rho- mutant cells, pH 6.05, delta pH 1.55 or -91 mV; starved cells, pHi 5.70, delta pH 1.20 or -71 mV. The proton conductors, DNP and PCP produce a decrease in pHi and delta pH and inhibition of L-leucine entrance by system S1, high affinity and low velocity and system S2, low affinity and high velocity. The obtained values of delta pH decrease and L-leucine transport inhibition, demonstrate that there is no strict relationship between the proton gradient across the cell membrane and the process of transport of L-leucine in yeast. PMID:2845476

de Bongioanni, L C; Ramos, E H

1988-01-01

204

Two tobacco genes induced by infection, elicitor and salicylic acid encode glucosyltransferases acting on phenylpropanoids and benzoic acid derivatives, including salicylic acid  

Microsoft Academic Search

Two tobacco genes (TOGT) with homology to glucosyltransferase genes known to be induced by salicylic acid (SA) also responded rapidly to a fungal elicitor or to an avirulent pathogen. SA, although an efficient inducer, was shown not to be essential in the signal transduction pathway regulating TOGT gene expression during the resistance response. Recombinant TOGT proteins produced in Escherichia coli

Laurence Fraissinet-Tachet; Rachel Baltz; Julie Chong; Serge Kauffmann; Bernard Fritig; Patrick Saindrenan

1998-01-01

205

Validation of an HPLC method for the quantification of ambroxol hydrochloride and benzoic acid in a syrup as pharmaceutical form stress test for stability evaluation  

Microsoft Academic Search

A method is described for ambroxol, trans-4-(2-amino-3,5-dibromobenzylamino) cyclohexanol hydrochloride, and benzoic acid separation by HPLC with UV detection at 247 nm in a syrup as pharmaceutical presentation. Optimal conditions were: Column Symmetry Shield RPC8, 5 ?m 2504.6 mm, and methanol\\/(H3PO4 8.5 mM\\/triethylamine pH=2.8) 40:60 v\\/v. Validation was performed using standards and the pharmaceutical preparation which contains the compounds described above.

Maarit Heinnen; Coral Barbas

2001-01-01

206

Comparison of the antitumor activity of DTIC and 1- p -(3,3-dimethyl-1-triazeno) benzoic acid potassium salt on murine transplantable tumors and their hematological toxicity  

Microsoft Academic Search

This study describes a comparison of 1-p-(3,3-dimethyl-1-triazeno)benzoic acid potassium salt (DM-COOK) and imidazole-4-carboxamide,5-(3,3-dimethyl-1-triazeno) (DTIC) with reference to antitumor activity on different murine tumors and hematological toxicity. DM-COOK appeared comparably or slightly more effective in L1210, P388, and M5 tumors in the mouse. However, when the treatment of mice bearing M5 with DM-COOK was combined with surgical removal of the primary

Tina Colombo; Maurizio D'Incalci

1984-01-01

207

Vapor phase oxidation of benzoic acid to phenol over a novel catalyst system consisting of NiO and NiFe{sub 2}O{sub 4}  

SciTech Connect

NiO and Fe{sub 2}O{sub 3} were found to show the catalytic activities for the vapor phase oxidation of benzoic acid to form phenol. Furthermore, the enhancement of the activity and phenol selectivity were achieved by combined Ni and Fe components prepared by precipitation. The calcination temperature and the atomic ratio of Ni to Fe were found to be important for the enhancement of activity. The homogeneous distribution profile of NiO and NiFe{sub 2}O{sub 4} on the surface and in the bulk of the catalyst is essential for the optimization of phenol formation. 32 refs., 7 figs., 4 tabs.

Miki, Jun; Asanuma, Minoru; Tachibana, Yakudo [NKK Corporation, Kawasaki (Japan)] [and others] [NKK Corporation, Kawasaki (Japan); and others

1995-02-01

208

Crystal structure of a new benzoic acid inhibitor of influenza neuraminidase bound with a new tilt induced by overpacking subsite C6  

PubMed Central

Background Influenza neuraminidase (NA) is an important target for antiviral inhibitors since its active site is highly conserved such that inhibitors can be cross-reactive against multiple types and subtypes of influenza. Here, we discuss the crystal structure of neuraminidase subtype N9 complexed with a new benzoic acid based inhibitor (2) that was designed to add contacts by overpacking one side of the active site pocket. Inhibitor 2 uses benzoic acid to mimic the pyranose ring, a bis-(hydroxymethyl)-substituted 2-pyrrolidinone ring in place of the N-acetyl group of the sialic acid, and a branched aliphatic structure to fill the sialic acid C6 subsite. Results Inhibitor 2 {4-[2,2-bis(hydroxymethyl)-5-oxo-pyrrolidin-1-yl]-3-[(dipropylamino)methyl)]benzoic acid} was soaked into crystals of neuraminidase of A/tern/Australia/G70c/75 (N9), and the structure refined with 1.55? X-ray data. The benzene ring of the inhibitor tilted 8.9 compared to the previous compound (1), and the number of contacts, including hydrogen bonds, increased. However, the IC50 for compound 2 remained in the low micromolar range, likely because one propyl group was disordered. In this high-resolution structure of NA isolated from virus grown in chicken eggs, we found electron density for additional sugar units on the N-linked glycans compared to previous neuraminidase structures. In particular, seven mannoses and two N-acetylglucosamines are visible in the glycan attached to Asn200. This long, branched high-mannose glycan makes significant contacts with the neighboring subunit. Conclusions We designed inhibitor 2 with an extended substituent at C4-corresponding to C6 of sialic acid-to increase the contact surface in the C6-subsite and to force the benzene ring to tilt to maximize these interactions while retaining the interactions of the carboxylate and the pyrolidinone substituents. The crystal structure at 1.55? showed that we partially succeeded in that the ring in 2 is tilted relative to 1 and the number of contacts increased, but one hydrophobic branch makes no contacts, perhaps explaining why the IC50 did not decrease. Future design efforts will include branches of unequal length so that both branches may be accommodated in the C6-subsite without conformational disorder. The high-mannose glycan attached to Asn200 makes several inter-subunit contacts and appears to stabilize the tetramer.

2012-01-01

209

Determination and pharmacokinetic study of 1-p-(3.3-dimethyl-1-triazeno) benzoic acid in cancer patients by capillary gas chromatography.  

PubMed

A capillary gas chromatographic method was developed for determining 1-p-(3.3-dimethyl-1-triazeno) benzoic acid in the plasma and urine of cancer patients under pharmacokinetic study. The drug was extracted with ethyl acetate and methylated with diazomethane. Octadelane (10 microg/ml) was added as internal standard. The separation was carried out on an OV-1 quartz capillary column, 15 m x 0.32 mm (0.52 microm), with high-purity nitrogen as carrier gas and flame ionization detector (FID) as detector. The column temperature was held at 130 degrees C for 9 min and then programmed to 240 degrees C, at a rate of 35 degrees C/min. The temperature of both injector and detector was 260 degrees C. The standard curve was linear from 0.4 to 40 microg/mL in plasma, and from 0.8 to 20 microg/mL in urine, with correlation coefficients of 0.9979 and 0.9932. The relative standard deviations (RSD) were less than 9.7%. The minimum recovery of this method was 81.8%. This method was applied to the pharmacokinetic studies of 1-p-(3.3-dimethyl-1-triazeno) benzoic acid in cancer patients after a single dose (i.v.) of 160, 420 or 760 mg/m(2) was administered. They all conformed to the two-compartment open model and showed linear pharmacokinetics. The excretion of this drug in the urine was minimal. PMID:11268045

Li, A Q; Zhao, X L

2001-04-01

210

[Rh(III) (Cp*)]-Catalyzed ortho-Selective Direct C(sp(2) )?H Bond Amidation/Amination of Benzoic Acids by N-Chlorocarbamates and N-Chloromorpholines. A Versatile Synthesis of Functionalized Anthranilic Acids.  

PubMed

A Rh(III) -catalyzed direct ortho-C?H amidation/amination of benzoic acids with N-chlorocarbamates/N-chloromorpholines was achieved, giving anthranilic acids in up to 85?% yields with excellent ortho-selectivity and functional-group tolerance. Successful benzoic acid aminations were achieved with carbamates bearing various amide groups including NHCO2 Me, NHCbz, and NHTroc (Cbz=carbobenzyloxy; Troc=trichloroethylchloroformate), as well as secondary amines, such as morpholines, piperizines, and piperidines, furnishing highly functionalized anthranilic acids. A stoichiometric reaction of a cyclometallated rhodium(III) complex of benzo[h]quinoline with a silver salt of N-chlorocarbamate afforded an amido-rhodium(III) complex, which was isolated and structurally characterized by X-ray crystallography. This finding confirmed that the C?N bond formation results from the cross-coupling of N-chlorocarbamate with the aryl-rhodium(III) complex. Yet, the mechanistic details regarding the C?N bond formation remain unclear; pathways involving 1,2-aryl migration and rhodium(V)- nitrene are plausible. PMID:24596116

Ng, Fo-Ning; Zhou, Zhongyuan; Yu, Wing-Yiu

2014-04-01

211

Validation of an HPLC method for the quantification of ambroxol hydrochloride and benzoic acid in a syrup as pharmaceutical form stress test for stability evaluation.  

PubMed

A method is described for ambroxol, trans-4-(2-amino-3,5-dibromobenzylamino) cyclohexanol hydrochloride, and benzoic acid separation by HPLC with UV detection at 247 nm in a syrup as pharmaceutical presentation. Optimal conditions were: Column Symmetry Shield RPC8, 5 microm 250 x 4.6 mm, and methanol/(H(3)PO(4) 8.5 mM/triethylamine pH=2.8) 40:60 v/v. Validation was performed using standards and the pharmaceutical preparation which contains the compounds described above. Results from both standards and samples show suitable validation parameters. The pharmaceutical grade substances were tested by factors that could influence the chemical stability. These reaction mixtures were analysed to evaluate the capability of the method to separate degradation products. Degradation products did not interfere with the determination of the substances tested by the assay. PMID:11248495

Heinnen, M; Barbas, C

2001-03-01

212

Bis(?2-benzoato-?2 O:O?)bis-[(benzoato-?2 O,O?)bis(4,4?-bi-pyridine-?N)cobalt(II)]-benzoic acid (1/6)  

PubMed Central

In the title compound, [Co2(C7H5O2)4(C10H8N2)4]6C6H5COOH, the centrosymmetric cobalt dimer co-crystallizes with six molecules of benzoic acid. Each CoII atom is coordinated by four O atoms in a distorted square-planar arrangement while the N atoms are located in apical positions. The dihedral angles between the rings comprising each of the 4,4?-bipyridyl ligands are 25.2?(2) and 22.8?(2). In the crystal, the three-dimensional network is assembled by OH?O and CH?O hydrogen bonds.

Pena-Rodriguez, Rodolfo; Rivera, Jose Maria; Colorado-Peralta, Raul; Duarte-Hernandez, Angelica Maria; Flores-Parra, Angelina

2014-01-01

213

Bis(?2-benzoato-?(2) O:O')bis-[(benzoato-?(2) O,O')bis(4,4'-bi-pyridine-?N)cobalt(II)]-benzoic acid (1/6).  

PubMed

In the title compound, [Co2(C7H5O2)4(C10H8N2)4]6C6H5COOH, the centrosymmetric cobalt dimer co-crystallizes with six mol-ecules of benzoic acid. Each Co(II) atom is coordinated by four O atoms in a distorted square-planar arrangement while the N atoms are located in apical positions. The dihedral angles between the rings comprising each of the 4,4'-bipyridyl ligands are 25.2?(2) and 22.8?(2). In the crystal, the three-dimensional network is assembled by O-H?O and C-H?O hydrogen bonds. PMID:24526949

Pea-Rodrguez, Rodolfo; Rivera, Jos Mara; Colorado-Peralta, Ral; Duarte-Hernndez, Anglica Mara; Flores-Parra, Angelina

2014-01-01

214

2-[(1H-Benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester: Crystal structure, DFT calculations and biological activity evaluation  

NASA Astrophysics Data System (ADS)

In the present study, structural properties of 2-[(1H-benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester have been studied extensively by spectral methods and X-ray crystallography. Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, NMR and electronic transitions were carried out by DFT using B3LYP functional combined with 6-31G(d) basis set. Natural bond orbitals (NBO) analysis and frontier molecular orbitals were performed at the same level of theory. DFT calculations showed good agreement between the theoretical and experimental values of optimized and X-ray structure as well as between the vibrational and NMR spectroscopy. The title compound was screened for its antibacterial activity referring to Tetracycline as standard antibacterial agent.

Ghani, Nour T. Abdel; Mansour, Ahmed M.

2011-10-01

215

The improvement of the anticancer effect of a novel compound benzoic acid, 2-hydroxy-, 2-D-ribofuranosylhydrazide (BHR) loaded in solid lipid nanoparticles.  

PubMed

A novel drug delivery system consisting of benzoic acid, 2-hydroxy-, 2-D-ribofuranosylhydrazide (BHR)-loaded solid lipid nanoparticles (BHR-SLNs) was prepared using the emulsification-evaporation technique. The mean particle size of the BHR-SLNs measured by photon correlation spectroscopy was about 75nm. BHR-SLN morphology was assessed by transmission electron microscopy and atomic force microscopy. The drug entrapment efficiency was 70.2%, as determined via Sephadex gel chromatography and high-performance liquid chromatography. Drug release assessment in vitro showed that BHR was gradually released from SLNs in a time-dependent manner. Furthermore, treatment of 293T and Hela cells with BHR-SLNs demonstrated that BHR-SLNs were less toxic to normal cells while more effective in antitumor potency compared with the BHR drug alone. The results imply that BHR-SLNs could be considered as a promising antitumor drug system for a range of new therapeutic applications. PMID:23054988

Wang, Mei; Qin, Lili; Li, Kun; Zhu, Rongrong; Wang, Wenrui; Wang, Shilong

2012-12-01

216

Novel mixed ligand di-n-butyltin(IV) complexes derived from acylpyrazolones and fluorinated benzoic acids: synthesis, characterization, cytotoxicity and the induction of apoptosis in Hela cancer cells.  

PubMed

Twenty one novel mixed ligand di-n-butyltin(IV) complexes [(n)Bu2SnAL] (A = substituted 4-acyl-5-pyrazolone, and L = fluorinated benzoic acid) were prepared by condensation of di-n-butyltin(IV) oxide with HL and HA in 1:1:1 molar ratio in refluxing methanol. All of the complexes were characterized by elemental analyses, IR, NMR ((1)H, (13)C, (119)Sn) and in four cases by X-ray diffraction. Cytotoxicity of the compounds was studied against two human cancer cell lines (KB and Hela) by means of the MTT assay compared to cisplatin, featuring IC?? values in the low micromolar range. Hela cancer cell apoptosis-induced by 2 was examined by flow cytometry analysis, and preliminary results showed that 2 at concentrations of more than 1.0 ?M can induce apoptosis. PMID:24583378

Zhao, Bin; Shang, Xianmei; Xu, Ling; Zhang, Wendian; Xiang, Guangya

2014-04-01

217

Inhibition of soluble epoxide hydrolase by trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB) is protective against ischemia reperfusion injury  

PubMed Central

Arachidonic acid, a polyunsaturated fatty acid, can be metabolized to cardioprotective epoxyeicosatrienoic acids (EETs) by cytochrome P450 epoxygenases, which are subsequently hydrolyzed to less bioactive dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). To study the effects of pharmacological inhibitor of sEH (sEHi), C57BL6 mice hearts were perfused in Langendorff mode for 40min of baseline and subjected to 30min of global no-flow ischemia followed by 40 min of reperfusion. Hearts were perfused with the sEHi, trans-4-[4-(3-adamantan-1-y1-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB; 0.05 M, 0.1 M, 0.5 M and 1 M). To study the mechanism(s), hearts were perfused with 0.1 M t-AUCB in the presence or absence of putative EET receptor antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 10 M) or phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin (200 nM) or LY294002 (5 M). Infarct size was determined at the end of 2 h reperfusion by TTC staining. Inhibition of sEH by t-AUCB significantly improved postischemic left ventricular developed pressure (LVDP) recovery and reduced the infarct size following ischemia-reperfusion, as compared to control hearts. Perfusion with 14,15-EEZE, wortmannin or LY294002 prior to ischemia abolished the cardioprotective phenotype; however, co-perfusion of both t-AUCB and 11,12-EET did not result in an additive effect on improved LVDP recovery. Together, our data suggest that pharmacological inhibition of sEH by t-AUCB is cardioprotective.

Chaudhary, Ketul R.; Abukhashim, Mohamed; Hwang, Sung Hee; Hammock, Bruce D.; Seubert, John M.

2009-01-01

218

Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: A kinetic approach  

NASA Astrophysics Data System (ADS)

The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation.

Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K.; Mukherjee, Kakali; Saha, Bidyut

2013-05-01

219

Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: a kinetic approach.  

PubMed

The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation. PMID:23501718

Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K; Mukherjee, Kakali; Saha, Bidyut

2013-05-15

220

4,4'-{[1,2-Phenyl-enebis(methyl-ene)]bis-(-oxy)}di-benzoic acid di-methyl-formamide disolvate.  

PubMed

In the title solvate, C22H18O62C3H7NO, the complete dicarboxylic acid molecule is generated by a crystallographic twofold axis, which bisects the central benzene ring and one N,N-di-methyl-formamide solvent mol-ecule. The dihedral angle between the central and pendant benzene rings is 54.53?(5) while that between the pendant rings is 45.44?(5). In the crystal, the acid molecules are linked to the solvent molecules via O-H?O and weak C-H?O hydrogen bonds. Further weak C-H?O inter-actions link adjacent acid mol-ecules into a three-dimensional network. PMID:24860345

Qiu, Zhen-Zhe; Jing, Bi; Li, Qiu-Xia; Zhu, Ai-Xin

2014-05-01

221

Adsorption of benzoic acid on pure and cupric ion-modified hydroxyapatite: implications for design of a coupling agent to dental polymer composites.  

PubMed

The adsorption isotherms of benzoic acid on synthetic hydroxyapatite (containing about 1.5 monolayers of physisorbed water) were studied from ethanol, dimethylsulfoxide, p-dioxane, methylene chloride, and benzene to discern the role of solvent in the process. The adsorption is reversible from the first three solvents and follows the Langmuir plots. It is irreversible from the last two, and a constant amount of absorbent is removed from solutions above a certain concentration. The isotherms of potassium benzoate on the apatite from ethanol and dimethyl sulfoxide were reversible. The isotherms of the acid on cupric ion-modified apatite surfaces from ethanol and benzene were identical with those obtained on the pure hydroxyapatite. This may demonstrate that any "surface chelation" with the cation may not be a significant factor for adsorption to occur. The adsorptive behavior seems to depend upon the interplay of hydrogen-bonding among the solute, the solvent, and the hydrated apatite surface. The capability of a solvent to hydrogen-bond may determine whether adsorption from it will be reversible or irreversible. Based upon its compatibility with a solvent, the benzene ring is upright or lies flat on the surface. The adsorbed molecules rotate about the center of the carboxylate groups which are hydrogen-bonded to the surface. These factors should be considered in designing or selecting a suitable surface-active moiety for a coupling agent between tooth mineral and a restorative resin. PMID:3009580

Misra, D N

1986-05-01

222

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

NASA Astrophysics Data System (ADS)

Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu0.5L]n (1), [Cu(HL)2Cl2]n (2), [Cu(HL)2Cl2(H2O)] (3), [Cu(L)2(H2O)]n (4) and [Cu(L)(phen)(HCO2)]n (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl-, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units -Cu-O-Cu-O- are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated.

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

2014-07-01

223

Sequestration of prenylated benzoic acid and chromenes by Naupactus bipes (Coleoptera: Curculionidae) feeding on Piper gaudichaudianum (Piperaceae)  

Microsoft Academic Search

The curculionid beetle Naupactus\\u000a bipes (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) has shown feeding preference for leaves of Piper gaudichaudianum, demonstrating an unexpected specificity for an insect considered to be a generalist. The leaves of P. gaudichaudianum contain the prenylated chromenes gaudichaudianic acid (4, major compound) and its methyl ester (5) in addition to a chromene (3) lacking one prenyl residue.

Clcio S. Ramos; Sergio A. Vanin; Massuo J. Kato

2009-01-01

224

Blockade of human neutrophil activation by 2-[2-propyl-3-[3-[2-ethyl-4-(4-fluorophenyl)-5-hydroxyphenoxy]propoxy]phenoxy]benzoic acid (LY293111), a novel leukotriene B 4 receptor antagonist  

Microsoft Academic Search

Leukotriene B4 (LTB4), a naturally occurring pro-inflammatory product of arachidonic acid metabolism, has been associated with human inflammatory disease. This study compares the abilities of two LTB4 receptor antagonists, 2-[2-propyl-3-[3-[2-ethyl-4-(4-fluorophenyl)-5-hydroxyphenoxy]-propoxy]phenoxy]benzoic acid (LY293111) and 7-[3-(4-acetyl-3-methoxy-2-propylphenoxy)-propoxy]-3, 4-dihydro-8-propyl-2H-1-benzopyran-2-carboxylic acid (SC-41930), to displace LTB4 binding and their functional blockade of human neutrophil activation. LY293111 inhibited the binding of [3H]LTB4 with a Ki, of 25

Philip Marder; J. Scott Sawyer; Larry L. Froelich; Larry L. Mann; Stephen M. Spaethe

1995-01-01

225

[Comparative study on separation of p-aminobenzoic and p-hydroxy-benzoic acids by reactive extraction].  

PubMed

The comparative study on reactive extraction of p-aminobenzoic and p-hydroxybenzoic acid with Amberlite LA-2 and D2EHPA in two solvents with different polarity (n-heptane and dichloromethane) indicated that the nature of the specific substituents, extractant type and solvent polarity control the extraction mechanism. Although the reactive extraction with Amberlite LA-2 of the two acids occurs by means of rather similar interfacial reactions, the extraction with D2EHPA is based on different mechanisms, due to the participation of the two different substituents of aminic and phenolic type. In all cases, the most efficient extractions have been reached for the combination Amberlite LA-2-dichloromethane. PMID:20209796

Galaction, Anca-Irina; Ca?caval, D

2008-01-01

226

3-Eth-oxy-carbonyl-2-hy-droxy-6-meth-oxy-4-methyl-benzoic acid.  

PubMed

The title compound, C(12)H(14)O(6), a substituted isophthalic acid monoester which was isolated from the lichen Thamnolia vermicularis var. subuliformis, displays intra-molecular carbox-yl-meth-oxy O-H?O and hy-droxy-carboxyl O-H?O hydrogen-bonding inter-actions. The terminal methyl group of the ethyl ester is disordered over two sets of sites with occupancies of 0.599?(19) and 0.401?(19). PMID:22590305

Deng, Yun-Xia; Guo, Tao; Xie, Hui; Pan, Sheng-Li

2012-05-01

227

New bitter-masking compounds: hydroxylated benzoic acid amides of aromatic amines as structural analogues of homoeriodictyol.  

PubMed

Starting from the known bitter-masking flavanones eriodictyol and homoeriodictyol from herba santa some structurally related hydroxybenzoic acid amides of benzylamines were synthesized and evaluated as masking agents toward bitterness of caffeine by sensory methods. The closest structural relatives of homoeriodictyol, the hydroxybenzoic acid vanillylamides 5-9, were the most active and were able to reduce the bitterness of a 500 mg L(-1) caffeine solution by about 30% at a concentration of 100 mg L(-1). 2,4-Dihydroxybenzoic acid vanillylamide 7 showed a clear dose-dependent activity as inhibitor of the bitter taste of caffein between 5 and 500 mg L(-1). Additionally, it was possible to reduce the bitterness of quinine and salicine but not of the bitter peptide N-l-leucyl-l-tryptophan. Combinations of homoeriodictyol and amide 7 showed no synergistic or antagonistic changes in activity. The results for model compound 7 suggested that the hitherto unknown masking mechanism is probably the same for flavanones and the new amides. In the future, the new amides may be alternatives for the expensive flavanones to create flavor solutions to mask bitterness of pharmaceuticals or foodstuffs. PMID:17061836

Ley, Jakob P; Blings, Maria; Paetz, Susanne; Krammer, Gerhard E; Bertram, Heinz-Jrgen

2006-11-01

228

Viper venom-induced inflammation and inhibition of free radical formation by pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from anantamul (Hemidesmus indicus R. BR) root extract.  

PubMed

The present investigation explored the possible venom neutralizing effect of a pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from the methanolic root extract of Hemidesmus indicus R.Rr. 2-OH-4-MeO benzoic acid possessed potent anti-inflammatory, antipyretic and antioxidant properties. The compound effectively neutralized inflammation induced by Vipera russelli venom in male albino mice and reduced cotton pellet-induced granuloma in rats. The compound produced a significant fall in body temperature in yeast-induced pyrexia in rats but did not change the normothermic body temperature. The compound effectively neutralized viper venom-induced changes in serum phosphatase and transaminase activity in male albino rats. It also neutralized free radical formation as estimated by TBAPS and superoxide dismutase activities. The antisnake venom activity of the pure compound is partly mediated through the above physiological process. PMID:9604294

Alam, M I; Gomes, A

1998-01-01

229

Application of ChemDraw NMR Tool: Correlation of Program-Generated (Super 13)C Chemical Shifts and pK[subscript a] Values of Para-Substituted Benzoic Acids  

ERIC Educational Resources Information Center

A study uses the ChemDraw nuclear magnetic resonance spectroscopy (NMR) tool to process 15 para-substituted benzoic acids and generate (super 13)C NMR chemical shifts of C1 through C5. The data were plotted against their pK[subscript a] value and a fairly good linear fit was found for pK[subscript a] versus delta[subscript c1].

Hongyi Wang

2005-01-01

230

Synthesis of chitosan resin possessing 3,4-diamino benzoic acid moiety for the collection\\/concentration of arsenic and selenium in water samples and their measurement by inductively coupled plasma-mass spectrometry  

Microsoft Academic Search

A chitosan resin functionalized with 3,4-diamino benzoic acid (CCTS-DBA resin) was newly synthesized by using a cross-linked chitosan (CCTS) as base material. The adsorption behavior of trace amounts of elements on the CCTS-DBA resin was examined by the pretreatment with a mini-column and measurement of the elements by inductively coupled plasma-Mass spectrometry (ICPMS). Arsenic(V) could be retained on the CCTS-DBA

Akhmad Sabarudin; Koji Oshita; Mitsuko Oshima; Shoji Motomizu

2005-01-01

231

Synthesis, electrochemical, structural, spectroscopic and biological activities of mixed ligand copper (II) complexes with 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid and nitrogenous bases  

NASA Astrophysics Data System (ADS)

Three new copper (II) complexes viz. [Cu(L1)(bipy)]?2H2O 1, [Cu(L1)(dmp)]?CH3CN 2, [Cu(L1)(phen)] 3 where L1H2 = 2-{[(Z)-(5-bromo-2-hydroxyphenyl)methylidene]amino}benzoic acid, bipy = 2,2?-bipyridine; dmp = 2,9-dimethyl 1,10-phenanthroline, phen = 1,10-phenanthroline have been synthesized and characterized by physic-chemical and spectroscopic methods. The solid-state structures of 1 and 2 were determined by single crystal X-ray crystallography, which revealed distorted square pyramidal geometry. In solid-state structure, 1 is self-assembled via intermolecular ?? stacking and the distances between centroids of aromatic ring is 3.525 . L1H2 is a diprotic tridentate Schiff base ligand having ONO donor site. Infrared spectra, ligand field spectra and magnetic susceptibility measurements agree with the observed crystal structures. The EPR spectra of these complexes in frozen DMSO solutions showed a single at g ca. 2. The trend in g-value (g|| > g? > 2.0023) suggests that the unpaired electron on copper (II) has d character. Copper (II) complexes 1-3 yielded an irreversible couple corresponding to the Cu (II)/Cu (I) redox process. Superoxide dismutase activity of all these complexes has been revealed to catalyze the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed. Antimicrobial and antifungal activities of these complexes were also investigated.

Choudhary, Mukesh; Patel, R. N.; Rawat, S. P.

2014-02-01

232

Modulation of Cyclins, p53 and Mitogen-Activated Protein Kinases Signaling in Breast Cancer Cell Lines by 4-(3,4,5-Trimethoxyphenoxy)benzoic Acid  

PubMed Central

Despite the advances in cancer therapy and early detection, breast cancer remains a leading cause of cancer-related deaths among females worldwide. The aim of the current study was to investigate the antitumor activity of a novel compound, 4-(3,4,5-trimethoxyphenoxy)benzoic acid (TMPBA) and its mechanism of action, in breast cancer. Results indicated the relatively high sensitivity of human breast cancer cell-7 and MDA-468 cells towards TMPBA with IC50 values of 5.9 and 7.9 ?M, respectively compared to hepatocarcinoma cell line Huh-7, hepatocarcinoma cell line HepG2, and cervical cancer cell line Hela cells. Mechanistically, TMPBA induced apoptotic cell death in MCF-7 cells as indicated by 4?,6-diamidino-2-phenylindole (DAPI) nuclear staining, cell cycle analysis and the activation of caspase-3. Western blot analysis revealed the ability of TMPBA to target pathways mediated by mitogen-activated protein (MAP) kinases, 5? adenosine monophosphate-activated protein kinase (AMPK), and p53, of which the concerted action underlined its antitumor efficacy. In addition, TMPBA induced alteration of cyclin proteins expression and consequently modulated the cell cycle. Taken together, the current study underscores evidence that TMPBA induces apoptosis in breast cancer cells via the modulation of cyclins and p53 expression as well as the modulation of AMPK and mitogen-activated protein kinases (MAPK) signaling. These findings support TMPBAs clinical promise as a potential candidate for breast cancer therapy.

Lee, Kuan-Han; Ho, Wen-Yueh; Wu, Shu-Jing; Omar, Hany A.; Huang, Po-Jui; Wang, Clay C. C.; Hung, Jui-Hsiang

2014-01-01

233

Linear free energy relationships applied to the reactivity and the 13C NMR chemical shifts in 4-[[(substituted phenyl)imino]methyl]benzoic acids  

NASA Astrophysics Data System (ADS)

Linear free energy relationships (LFER) were applied to the kinetic data and 13C NMR chemical shifts in 4-[[(substituted phenyl)imino]methyl]benzoic acids. The correlation analysis for the kinetic data and substituent-induced chemical shifts (SCS) with ? using single substituent parameter (SSP), as well as inductive (?I) and various resonance (?R) parameters using dual-substituent parameter (DSP), were carried out. The presented calculations account satisfactorily for the polar and resonance substituent effects having similar contributions at all carbons studied. Negative ? values were found for several correlations (reverse substituent effect). Exceptionally good Hammett correlation of 13C NMR chemical shifts of azomethine carbon with electrophilic substituent constants ?+ indicates a significant resonance interaction in the aniline part of molecules. The conformations of investigated compounds have been studied by the use of DFT method, and together with 13C NMR chemical shifts and kinetic data, give a better insight into the influence of such a structure on the transmission of electronic substituent effects. New ? constants for substituted phenyliminomethyl group have been calculated.

Marinkovi?, Aleksandar D.; Jovanovi?, Bratislav .; Assaleh, Fathi H.; Vajs, Vlatka V.; Jurani?, Milan I.

2012-03-01

234

Induction of apoptosis by 4-(3-(tert-butylamino)imidazo[1,2-?]pyridine-2-yl) benzoic acid in breast cancer cells via upregulation of PTEN.  

PubMed

We have previously reported that 4-(3-(tert-butylamino)imidazo[1,2-?]pyridine-2-yl)benzoic acid, a bicyclic N-fused aminoimidazoles derivative (BNFA-D), possesses anticancer potentiality against breast and kidney cancer cells with minimal toxicities to corresponding normal cells. Here, we explored the mechanism of action of BNFA-D in breast cancer cells using multiple cell-based assays such as MTT, DAPI, FACS, Western blot, and immunoprecipitation. BNFA-D caused apoptosis by upregulating PTEN leading to inhibition of Wnt/TCF signaling cascade and arresting S phase in breast cancer cells. Expression levels of ?-catenin, cyclin D1, C-MYC, and phospho-AKT (Ser(473)) decreased with simultaneous increase in the levels of GSK3?, CK1, and PTEN in BNFA-D-treated MCF-7 cells. Interestingly, silencing of PTEN in breast cancer cells reversed the phenomenon of Wnt/TCF signaling cascade inhibition after BNFA-D treatment. PMID:24330847

Siddharth, Sumit; Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan; Choudhuri, Tathagata; Kundu, Chanakya Nath

2013-01-01

235

Simultaneous determination of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid, in rat and human plasma by high-performance liquid chromatography.  

PubMed

A rapid, selective and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for the simultaneous determination of triflusal and its major active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid (HTB), in rat and human plasma. HPLC analysis was carried out using a 5-microm particle size, C18-bonded silica column and acetonitrile-methanol-water (25:10:65, v/v/v) as the mobile phase and UV detection at 234 nm. Furosemide was used as the internal standard. The method involved extraction with an acetonitrile-chloroform mixture (60:40, v/v) and evaporation to dryness with nitrogen stream. The chromatograms showed good resolution and sensitivity and no interferences by plasma constituents. The mean absolute recovery for human plasma was 93.5 +/- 4.2% for triflusal and 98.5 +/- 3.1% for HTB. The lower limits of quantification of triflusal and HTB in human plasma were 20 and 100 ng/ml, respectively. The calibration curves in human plasma were linear over the concentration range 0.02-5.0 microg/ml for triflusal and 0.1-200.0 microg/ml for HTB with correlation coefficients greater than 0.999 and with inter- or intra-day coefficients of variation (CV) not exceeding 10.0%. This assay procedure was applied to the study of metabolite pharmacokinetics of triflusal and HTB in rat and human. PMID:14643505

Cho, Hea-Young; Jeong, Tae-Jin; Lee, Yong-Bok

2003-12-25

236

FT-IR, FT-Raman, NMR and UV-vis spectra, vibrational assignments and DFT calculations of 4-butyl benzoic acid  

NASA Astrophysics Data System (ADS)

The solid phase FTIR and FT-Raman spectra of 4-butyl benzoic acid (4-BBA) have been recorded in the regions 400-4000 and 50-4000 cm -1, respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-311++G(d,p) as basis set. The vibrational frequencies were calculated for monomer and dimer by DFT method and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. 13C and 1H NMR spectra were recorded and 13C and 1H nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compound was recorded in the region 200-400 nm and the electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman intensities, chemical shifts and absorption wavelengths were compared with the available experimental data of the molecule.

Karabacak, M.; Cinar, Z.; Kurt, M.; Sudha, S.; Sundaraganesan, N.

2012-01-01

237

The structure of 4-(trimethylammonium)benzoic acid chloride studied by X-ray diffraction, DFT calculations, NMR and FTIR spectroscopy  

NASA Astrophysics Data System (ADS)

The effects of hydrogen bonding, inter- and intramolecular electrostatic interactions on the structure of 4-(trimethylammonium)benzoic acid chloride ( 1), 4NMeBACl, in the crystal and in the optimised molecule ( 2-4) have been studied by X-ray diffraction, DFT calculations, solid-state FTIR and in solutions by 1H and 13C NMR spectroscopy. In the crystal, the carboxy group is protonated and forms a hydrogen bond with the chloride ion with the O-H⋯Cl - distance of 2.952(2) . The Cl - ion is involved in three short N +⋯Cl - interionic electrostatic interactions. In the optimised molecules, according to the B3LYP/6-311++ G( d, p) calculations, the Cl - ion is engaged in slightly longer hydrogen bonds (O-H⋯Cl - = 3.0253-3.1427 ) and the electrostatic contact N +⋯Cl - is longer than those in the crystal. Both proton and carbon chemical shifts of 4NMeBACl are solvent dependent. The magnetic isotropic shielding constants, ?calc, were calculated by the GIAO/B3LYP/6-311++ G( d, p) approach and linear correlations with 1H and 13C chemical shifts were obtained.

Szafran, M.; Katrusiak, A.; Dega-Szafran, Z.; Kowalczyk, I.

2011-06-01

238

Influence of pH, benzoic acid, glutathione, EDTA, 4-hexylresorcinol, and sodium chloride on the pressure inactivation kinetics of mushroom polyphenol oxidase.  

PubMed

Pressure inactivation of mushroom PPO was studied for pH values ranging from 4 to 8, and the effect of some antibrowning agents on the pressure stability of mushroom PPO at pH 6.5 was evaluated. pH reduction below 6.5 resulted in a lowered inactivation threshold pressure and an increase of the absolute value of the activation volume (or a decrease of the z(p) value), the latter two parameters reflecting the pressure dependency of the inactivation rate constant. An increase in pH from 6.5 to 8, on the other hand, did only marginally affect the pressure stability of the enzyme. Mushroom PPO at pH 6.5 was markedly sensitized toward pressure by the presence of 2.5 mM 4-hexylresorcinol and slightly stabilized by the presence of 5 mM EDTA. The presence of 5 mM glutathione, sodium chloride, or benzoic acid caused no significant alteration of the enzyme pressure stability. Only in the presence of 4-hexylresorcinol, significant changes of the activation volume and z(p) value were noticed. PMID:10552679

Weemaes, C A; Ludikhuyze, L R; Van den Broeck, I; Hendrickx, M E

1999-09-01

239

Behavior-selective Apoptotic Capacity of 4-(3,4,5-Trimethoxyphenoxy) Benzoic Acid and its Methyl Derivatives on Two Breast Cancer Cell Lines.  

PubMed

Breast cancer is one of the most common tumors in females. The therapeutic resistance of breast cancer has motivated the development of new agents for prevention and treatment. For the present study, several compounds were designed and analyzed for their antitumor activity in many cancer cell lines. 4-(3,4,5-Trimethoxyphenoxy) benzoic acid (compound 1) and its derivatives were selected for studying the anti-proliferative and cytotoxic effects on five human cancer cell lines. Results indicated that compounds 1 and 2 significantly suppressed the cell viability of MCF-7 and MDA-MB-468 cancer cells. However, compounds 1 and 2 had only minor effects on HepG2, Huh-7, and Hela cells. Moreover, compounds 1 and 2 exhibited a novel anti-tumor activity through the induction of cell-cycle arrest at G2/M and apoptosis in MCF-7 and MDA-MB-486 breast cancer cells. Both compounds reduced colony-forming ability in MCF-7 cells. Flow cytometric analysis indicated that caspase-3 activity was increased in response to treatment with compounds 1 and 2. Taken together, these findings suggest that the novel compounds 1 and 2 are potential anticancer agents with clinical promise for breast cancer therapy. PMID:24692713

Lee, Kuan-Han; Ho, Wen-Yueh; Wu, Shu-Jing; Cheng, Tsung-Lin; Huang, Po-Jui; Wang, Clay C C; Hung, Jui-Hsiang

2014-04-01

240

Dielectric study of equimolar acetaminophen-aspirin, acetaminophen-quinidine, and benzoic acid-progesterone molecular alloys in the glass and ultraviscous states and their relevance to solubility and stability.  

PubMed

Equimolar mixtures of acetaminophen-aspirin, acetaminophen-quinidine, and benzoic acid-progesterone have been vitrified and dielectric properties of their glassy and ultraviscous alloys have been studied. For 20 K/min heating rate, their T(g)s are 266, 330, and 263 K, respectively. The relaxation has an asymmetric distribution of times, and the distribution parameter increases with increase in temperature. The dielectric relaxation time varies with T according to the Vogel-Fulcher-Tammann equation, log(10)(tau(0)) = A(VFT) + [B(VFT)/(T - T(0))], where A(VFT), B(VFT), and T(0) are empirical constants. The equilibrium permittivity is highest for the aspirin-acetaminophen and lowest for the benzoic acid-progesterone alloy, indicating a substantial interpharmaceutical hydrogen bonding that makes the alloy more stable against crystallization than the pure components. The benzoic acid-progesterone alloy is thermodynamically the most nonideal. It showed cold crystallization on heating, which is attributed to its relatively greater magnitude of the JG relaxation in relation to its alpha-relaxation. It is argued that the difference between the free energy of an alloy and the pure components would have an effect on the solubility. Studies of solution thermodynamics of a glassy molecular alloy may be useful for optimizing choice of components and composition to form molecular alloys and to impact drug delivery. PMID:19780138

Johari, G P; Kim, S; Shanker, Ravi M

2010-03-01

241

A rapid and sensitive UHPLC-MS/MS method for quantification of 2-(2-hydroxypropanamido) benzoic acid in rat plasma: application to a pharmacokinetic study.  

PubMed

A rapid, sensitive and high throughput UHPLC-MS/MS method was established and validated to assay the concentration of 2-(2-hydroxypropanamido) benzoic acid (HPABA), a promising anti-inflammatory drug, in rat plasma. Plasma samples were processed by liquid-liquid extraction with ethyl acetate and separated on a Shim-pack XR-ODS C18 column (75 mm3.0 mm, 2.2 ?m) at an isocratic flow rate of 0.4 mL/min using acetonitrile-0.1% formic acid in water (50:50, v/v) as mobile phase, and total run time was 2 min. MS/MS detection was accomplished in multiple reaction monitoring (MRM) mode with positive electrospray ionization. The calibration curve was linear over the concentration range of 0.01-50 ?g/mL with lower limit of quantification of 0.01 ?g/mL. The intra- and inter-day precisions were below 8.5% in terms of relative standard deviation (RSD), and the accuracy was within 4.0% in terms of relative error (RE). Extraction recovery, matrix effect and stability were satisfactory in rat plasma. The developed method was successfully applied to a pharmacokinetic study of HPABA following intragastric administration of 25, 50, 100mg/kg and an intravenous injection at a dose of 12.5 mg/kg to Sprague-Dawley rats. Results indicated that HPABA had linear pharmacokinetic properties within the tested intragastric dosage range and the absolute bioavailability was above 59.1%. PMID:24631710

Guan, Jiao; Zhao, Yunli; Zhu, Heyun; An, Zhenzhen; Yu, Yuming; Li, Ruijuan; Yu, Zhiguo

2014-07-01

242

The polyphenol 3, 4, 5 - tri-hydroxy benzoic acid inhibits indian daboia russelli venom and its hemorrhagic complex induced local toxicity.  

PubMed

Despite a long history on treatment and management of snakebite, as of now, no satisfactory cure exists to treat local toxicity, including anti-venom therapy. Several natural compounds from plants and their synthetic analogs have shown to be protective. In this study 3, 4, 5-tri-hydroxy benzoic acid, the gallic acid (GA) was tested against the local toxicity of Daboia russelli (DR) venom and its purified hemorrhagic complex (HC). GA inhibited in vitro proteolytic activity of both DR venom and HC but, it did not inhibit phospholipase activity of DR venom. GA inhibited hemorrhage, edema forming, dermo- and myonecrotic activities of both HC and DR venom in in vivo experiments. GA was particularly effective against hemorrhagic activity but, GA inhibition had a greater effect on HC when compared to DR venom. The inhibition was likely due to GA induced structural changes in HC as revealed by alterations in fluorescence emission and CD spectral properties. However, the inhibition was not due to chelating property of GA as suggested by UV-visible spectral studies. Inhibition of collagen type IV, laminin and fibronectin degradation essentially provided the biochemical basis for GA which inhibited local effects of HC as well as DR venom. Thus, the study appears highly promising to explore GA and its generics against ruthless local effects and perhaps systemic hemorrhage of DR and other snake bites as well. Further, these agents will possibly find an immense value in the regulation of matrix metalloproteases (MMPs) in processes such as wound healing, inflammation and in the treatment of cancer. PMID:21682684

Mahadeswaraswamy, Y H; Kumar, M S; Gowtham, Yashonandana J; Nagaraju, S; Girish, K S; Kemparaju, K

2011-01-01

243

The chemistry and preparation of tantalum complexes with 2,3-dihydroxy benzoic acid: Experimental and theoretical investigation  

NASA Astrophysics Data System (ADS)

The effect of 2,3-dihydroxybenzoic acid (2,3DHBA, pyrocatechuic acid) on the chloro-alkoxo-species [TaCl 5- x(OMe) x], formed by dissolving TaCl 5 in MeOH, has been studied. The coordination of 2,3DHBA-H 2- on Ta (V) replacing MeO-terminal groups was monitored via NMR spectroscopy. The yellow solid 1 was isolated from the mixture of TaCl 5, with neutral 2,3-DHBA, in MeOH. From this solid the elemental (C, H and Ta), the thermogravimetric analyses, the IR, NMR, ESR and electronic spectra support the formula Ta 2(2,3DHBA) 2(O) 2Cl 4(MeO) 4. The ESR spectrum of solid 1, at 4.2 K, shows a half-field signal apart from a multiline signal around g = 2, supporting evidence for semiquinone and Ta (IV) presence. The occurrence of superoxide radical, in the low temperature of ESR spectrum recording, cannot be ruled out. By heating the solid 1 at 500 C, an oxide phase showing porous character (SEM) and retaining CO 2 (IR), is evident. Solid 1 heated at 900 C, leads to the formation of ?-Ta 2O 5 orthorhombic phase, as the XRD pattern indicates. The hydrolytic process of solid 1, in aqueous solutions, has been studied; the presence of paramagnetic species generated in situ upon addition of base and the consequent degradative process of 2,3-DHBA, under aerobic conditions is obvious. In order to gain information for the structure of solid 1, DFT calculations have been performed for some theoretical models, based on the empirical formula of solid 1. The calculated structural and spectroscopic parameters have been correlated to experimental results. The energy optimized structures may give an idea about the way of MeCl and MeOMe formation as well some possible intermediates of the hydrolytic mechanism.

Hatzipanayioti, Despina; Kontotheodorou, Konstantinos

2011-03-01

244

Simultaneous determination of glucose, 1,5-anhydro-d-glucitol and related sugar alcohols in serum by high-performance liquid chromatography with benzoic acid derivatization.  

PubMed

A new, simple and sensitive pre-column high-performance chromatographic method for the determination of diabetes marker d-glucose, 1,5-anhydro-d-glucitol and related compounds is reported. Sugars (d-glucose, d-galactose, d-mannose, sucrose and arabinose) were derivatized with benzoic acid (BA) at 80 degrees C for 60 min. l-Fucose, fructose, d-lactose, l-rhamnose, arabinose and ascorbic acid were not reacted. Sugar alcohols (xylitol, erythritol, mannitol, sorbitol myo-inositol) were also derivatized with BA at 80 degrees C for 60 min. The fluorescence derivatives were separated on a TSK amide 80 column (4.6 mm i.d. x 250 mm, 5 microm) with acetonitrile-50 mm acetate buffer (pH 5.6; 4:96, v/v) as the mobile phase. The detection wavelength of beizoic acid derivatives was lambda(ex) 275 nm and lambda(em) 315 nm. The detection limits of sugars were 10-80 microg/mL. The calibration graphs were linear up to 10 mg/mL. The relative standard deviations of 500 microg/mL sugars were 7.0-7.3%. The proposed method was compared with the enzymatic photometric glucose analysis method (Glucose B-Test II Wako). The correlation coefficient was 0.83 (n = 20) and y = 0.82x + 5.91, where y and x are concentrations in microg/mL obtained by the proposed pre-column HPLC and enzyme-photometric method, respectively. The detection limits of sugar alcohols were 100-1000 ng/mL. The calibration graphs were linear to 50 microg/mL and relative standard deviations of 10 microg/mL were 7.2-8.2%. The 1,5-AG data by the proposed method was also compared with the enzymatic photometric 1,5-AG analysis method (Rana AG 1,5-AG determination kit, Nihon Kayaku) and good correlation (r = 0.91, n = 20) was also obtained. The proposed method was applied to the simultaneous determination of d-glucose, 1,5-AG and related sugar alcohols in serum from healthy males. PMID:16161184

Katayama, Masatoki; Matsuda, Yoshifumi; Kobayashi, Kensuke; Kaneko, Satoru; Ishikawa, Hiromichi

2006-05-01

245

40 CFR 721.1550 - Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1).  

Code of Federal Regulations, 2012 CFR

...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic...benzenediazonium, 4-(dimethylamino)-, salt with...

2012-07-01

246

40 CFR 721.1550 - Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic acid (1:1).  

Code of Federal Regulations, 2011 CFR

...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic...Benzenediazonium, 4-(di-methyl-amino)-, salt with 2-hy-droxy-5-sul-fo-benzoic...benzenediazonium, 4-(dimethylamino)-, salt with...

2011-07-01

247

2-[4,5-Difluoro-2-(2-Fluorobenzoylamino)-Benzoylamino]Benzoic Acid, an Antiviral Compound with Activity against Acyclovir-Resistant Isolates of Herpes Simplex Virus Types 1 and 2  

PubMed Central

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are responsible for lifelong latent infections in humans, with periods of viral reactivation associated with recurring ulcerations in the orofacial and genital tracts. In immunosuppressed patients and neonates, HSV infections are associated with severe morbidity and, in some cases, even mortality. Today, acyclovir is the standard therapy for the management of HSV infections. However, the need for novel antiviral agents is apparent, since HSV isolates resistant to acyclovir therapy are frequently isolated in immunosuppressed patients. In this study, we assessed the anti-HSV activity of the antiadenoviral compounds 2-[2-(2-benzoylamino)-benzoylamino]benzoic acid (benzavir-1) and 2-[4,5-difluoro-2-(2-fluorobenzoylamino)-benzoylamino]benzoic acid (benzavir-2) on HSV-1 and HSV-2. Both compounds were active against both viruses. Importantly, benzavir-2 had potency similar to that of acyclovir against both HSV types, and it was active against clinical acyclovir-resistant HSV isolates.

Islam, Koushikul; Edlund, Karin; Oberg, Christopher T.; Allard, Annika; Bergstrom, Tomas; Mei, Ya-Fang; Elofsson, Mikael

2012-01-01

248

4-({(Z)-5-[(Z)-3-Eth-oxy-4-hy-droxy-benzyl-idene]-3-methyl-4-oxo-1,3-thia-zolidin-2-yl-idene}amino)-benzoic acid dimethyl-formamide monosolvate  

PubMed Central

The molecular structure of the title compound, C20H18N2O5SC3H7NO, represents an essentially planar 5-benzylidene-thiazolidine moiety (r.m.s. deviation from planarity without ring substituents = 0.095?) to which the 4-aminobenzoic acid fragment is inclined at 76.23?(1). In the crystal, the benzoic acid molecules are arranged in layers parallel to [001] which are built up from inversion dimers held together by head-to-tail phenolcarboxy OH?O hydrogen bonds and head-to-tail ?? stacking interactions between the 5-benzylidene-thiazolidine moieties (ring centroid distance = 3.579?). These layers are separated by the dimethylformamide solvent molecules which are firmly anchored via a short OH?O hydrogen bond [O?O = 2.5529?(10)?] donated by the COOH group.

Kosma, Paul; Selzer, Edgar; Mereiter, Kurt

2012-01-01

249

Chromatographic Determination of Derivatives of p?Hydroxybenzoic Acid in Melissa officinalis by HPLC  

Microsoft Academic Search

This paper presents a fast method for the determination of phenolic compoundsbenzoic acids in Melissa officinalis. Soxhlet extraction has been optimized for the isolation of benzoic acids (gallic acid, p?hydroxybenzoic acid, protocatechuic acid, gentisic acid, vanillic acid, and syringic acid) from plant material. The conditions of Soxhlet extraction, such as solvent composition and extraction time were studied. The efficient extraction

Gabriela Karasov; Jozef Lehotay

2005-01-01

250

Synthesis and evaluation of novel 4-[(3H,3aH,6aH)-3-phenyl)-4,6-dioxo-2-phenyldihydro-2H-pyrrolo[3,4-d]isoxazol-5(3H,6H,6aH)-yl]benzoic acid derivatives as potent acetylcholinesterase inhibitors and anti-amnestic agents.  

PubMed

The present study was designed to synthesize and evaluate pyrrolo-isoxazole benzoic acid derivatives as potential acetylcholinesterase (AChE) inhibitors for the management of Alzheimer's disease. The synthesis of pyrrolo-isoxazole benzoic acid derivatives involved ring opening cyclization of p-aminobenzoic acid with maleic anhydride to yield maleanilic acid, which in turn afforded N-arylmaleimide via ring closed cyclization. Azomethine-N-oxides were obtained by condensation of N-arylhydroxylamine with differently substituted benzaldehydes followed by refluxing of N-arylmaleimide with differently substituted azomethine-N-oxides to pyrrolo-isoxazole benzoic acid derivatives as cis- and trans-stereoisomers. The synthesized compounds were evaluated in vitro for AChE inhibitory activity in rat brain homogenate with donepezil as standard AChE inhibitor. Thereafter, the most potent test compound was evaluated for in vitro butyrylcholinesterase inhibitory activity and in vivo memory evaluation in scopolamine (0.4mg/kg)-induced amnesia in mice by employing Morris water maze test. All pyrrolo-isoxazole benzoic acid derivatives demonstrated potent AChE inhibitory activity. Most of compounds exhibited similar activity to donepezil and four of them (7h, 7i, 8i, and 8h, IC(50)=19.11.9-17.51.5nM) displayed higher inhibitory activity as compared to donepezil (21.53.2nM) with compound 8ia (IC(50)=17.51.5nM) being the most active one. The test compound 8ia also ameliorated scopolamine-induced amnesia in mice in terms of restoration of time spent in target quadrant (TSTQ) and escape latency time (ELT). It may be concluded that pyrrolo-isoxazole benzoic acid derivatives may be employed as potential AChE inhibitors. PMID:22172310

Anand, Preet; Singh, Baldev

2012-01-01

251

DFT calculations, spectroscopic, thermal analysis and biological activity of Sm(III) and Tb(III) complexes with 2-aminobenzoic and 2-amino-5-chloro-benzoic acids.  

PubMed

The complexes of Sm(III) and Tb(III) with 2-aminobenzoic acid (anthranilic acid, AA) and 2-amino-5-chlorobenzoic acid (5-chloroanthranilic acid, AACl) were synthesized and characterized based on elemental analysis, IR and mass spectroscopy. The data are in accordance with 1:3 [Metal]:[Ligand] ratio. On the basis of the IR analysis, it was found that the metals were coordinated to bidentate anthranilic acid via the ionised oxygen of the carboxylate group and to the nitrogen of amino group. While in 5-chloroanthranilic acid, the metals were coordinated oxidatively to the bidentate carboxylate group without bonding to amino group; accordingly, a chlorine-affected coordination and reactivity-diversity was emphasized. Thermal analyses (TGA) and biological activity of the complexes were also investigated. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (d,p)_ level of theory have been carried out to investigate the equilibrium geometry of the ligand. The optimized geometry parameters of the complexes were evaluated using SDDALL basis set. Moreover, total energy, energy of HOMO and LUMO and Mullikan atomic charges were calculated. In addition, dipole moment and orientation have been performed and discussed. PMID:24835942

Essawy, Amr A; Afifi, Manal A; Moustafa, H; El-Medani, S M

2014-10-15

252

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

PubMed

A previously developed growth-no growth model for Listeria monocytogenes, based on nutrient broth data and describing the influence of water activity (a(w)), pH, and acetic acid concentrations, was validated (i) for a variety of L. monocytogenes strains and (ii) in a laboratory-made, mayonnaise-based surimi salad (as an example of a mayonnaise-based salad). In these challenge tests, the influence of the inoculation level was tested as well. Also, the influence of chemical preservatives on the growth probability of L. monocytogenes in mayonnaise-based salads was determined. To evaluate the growth-no growth model performance on the validation data, four quantitative criteria are determined: concordance index, % correct predictions, % fail-dangerous, and % fail-safe. First, the growth probability of 11 L. monocytogenes strains, not used for model development, was assessed in nutrient broth under conditions within the interpolation region. Experimental results were compared with model predictions. Second, the growth-no growth model was assessed in a laboratory-made, sterile, mayonnaise-based surimi salad to identify a possible model completeness error related to the food matrix, making use of the above-mentioned validation criteria. Finally, the effect on L. monocytogenes of common chemical preservatives (sorbic and benzoic acid) at different concentrations under conditions typical of mayonnaise-based salads was determined. The study showed that the growth-no growth zone was properly predicted and consistent for all L. monocytogenes strains. A larger prediction error was observed under conditions within the transition zone between growth-no growth. However, in all cases, the classification between no growth (P = 0) and any growth (P > 0) occurred properly, which is most important for the food industry, where outgrowth needs to be prevented in all instances. The results in the sterile mayonnaise-based salad showed again that the growth-no growth zone was well predicted but that also, in real food systems, a transition zone between growth and no growth exists. This became even more obvious for lower inoculation levels. The maximum-allowed concentration of benzoic and sorbic acid in mayonnaise-based salads, according to the European Union legislation, eliminated the growth of L. monocytogenes. Concentrations of 600 and 300 ppm were already sufficient to inhibit growth at 7 and 4 degrees C, respectively, under conditions associated with mayonnaise-based salads (pH 5.6; a(w), 0.985). PMID:17900091

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

2007-09-01

253

Synthesis of Mannich bases: 2-(3-Phenylaminopropionyloxy)-benzoic acid and 3-Phenylamino-1-(2,4,6-trimethoxy-phenyl)-propan-1-one, their toxicity, ionization constant, antimicrobial and antioxidant activities.  

PubMed

Mannich bases 2-(3-Phenylaminopropionyloxy)-benzoic acid (A) and 3-Phenylamino-1-(2,4,6-trimethoxy-phenyl)-propan-1-one (B) were synthesized. Structures were confirmed by ultraviolet/visible and infra-red spectroscopies. The ionization constant (pKa) values at 8.3 and 8.0 reported for compounds A and B, respectively, indicated that protonation might occur at physiological pH. The LC50 values of 145,595?g/ml (A) and 82,526?g/ml (B) obtained from Brine shrimp lethality testing showed that both compounds were non-toxic. The two compounds possessed significant antimicrobial activity against bacterial and fungal strains; Escherichia coli, Staphylococcus aereus, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonellae typhi, Candida albicans, Rhizopus stolonifer, Aspergillus niger and Penicillium notatum when compared with standards, gentamicin and tioconazole for bacteria and fungi, respectively. In vitro antioxidant screening by the DPPH free radical scavenging method and the scavenging effect on hydrogen peroxide showed that the compounds possessed significant antioxidant activity when compared with antioxidant standards ascorbic acid, butylated hydroxylanisole and ?-tocopherol. PMID:25038706

Oloyede, Ganiyat K; Willie, Itoro E; Adeeko, Oluwakemi O

2014-12-15

254

The co-crystal N,N?-bis-[(pyridin-1-ium-2-yl)meth-yl]ethane-dithio-amide bis-(2,6-di-nitro-benzoate)-2,6-di-nitro-benzoic acid (1/4)  

PubMed Central

The asymmetric unit of title co-crystal, C14H16N4S2 2+2C7H3N2O6 ?4C7H4N2O6, comprises a centrosymmetric dipyridinium dication, a 2,6-dinitrobenzoate anion and two independent 2,6-dinitrobenzoic acid molecules. The pyridinium rings are each approximately perpendicular to the central dithioamide unit [dihedral angle = 80.67?(12)]. The carboxylate/carboxylic acid groups are approximately perpendicular to the benzene ring to which they are attached [dihedral angles = 78.85?(16), 81.46?(19) and 71.28?(15)]. By contrast, the major twist exhibited by a nitro group is manifested in a dihedral angle of 32.66?(17). The most prominent feature of the crystal packing is linear supramolecular chains along [1-10], featuring OH?O(carboxylate) and pyridinium-NH?O hydrogen bonds. These are consolidated into a three-dimensional architecture by thioamidenitro NH?O, CH?O and ?? [inter-centroid distance = 3.524?(2)?] interactions. One of the nitro O atoms was refined over two sites; the major site was 0.65?(7) occupied.

Arman, Hadi D.; Miller, Tyler; Poplaukhin, Pavel; Tiekink, Edward R. T.

2013-01-01

255

Modeling, Synthesis and Biological Evaluation of Potential Retinoid-X-Receptor (RXR) Selective Agonists: Novel Halogenated Analogs of 4-[1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic Acid (Bexarotene)  

PubMed Central

The synthesis of halogenated analogs of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (1), known commonly as bexarotene, and their evaluation for retinoid-X-receptor (RXR)-specific agonist performance is described. Compound 1 is FDA approved to treat cutaneous T-cell lymphoma (CTCL); however, bexarotene treatment can induce hypothyroidism and elevated triglyceride levels, presumably by disrupting RXR heterodimer pathways for other nuclear receptors. The novel halogenated analogs in this study were modeled and assessed for their ability to bind to RXR and stimulate RXR homodimerization in an RXRE-mediated transcriptional assay as well as an RXR mammalian-2-hybrid assay. In an array of 8 novel compounds, 4 analogs were discovered to promote RXR-mediated transcription with comparable EC50 values as 1 and are selective RXR agonists. Our approach also uncovered a periodic trend of increased binding and homodimerization of RXR when substituting a halogen atom for a proton ortho to the carboxylic acid on 1.

Furmick, Julie K.; Kaneko, Ichiro; Walsh, Angela N.; Yang, Joanna; Bhogal, Jaskaran S.; Gray, Geoffrey M.; Baso, Juan C.; Browder, Drew O.; Prentice, Jessica L.S.; Montano, Luis A.; Huynh, Chanh C.; Marcus, Lisa M.; Tsosie, Dorian G.; Kwon, Jungeun S.; Quezada, Alexis; Reyes, Nicole M.; Lemming, Brittney; Saini, Puneet; van der Vaart, Arjan; Groy, Thomas L.; Marshall, Pamela A.; Jurutka, Peter W.; Wagner, Carl E.

2012-01-01

256

Determination of p K a values of some hydroxylated benzoic acids in methanolwater binary mixtures by LC methodology and potentiometry  

Microsoft Academic Search

An accurate estimation of pKa values in methanolwater binary mixtures is very important for several separation techniques such as liquid chromatography and capillary electrophoresis that use these solvent mixtures. In this study, the pKa values of 11 polyphenolic acids have been determined in methanolwater binary mixtures (10%, 20% and 30% (v\\/v)) by potentiometry, liquid chromatography (LC) and LC-DAD methodology.The results

F. Z. Erdemgil; S. ?anli; N. ?anli; G. zkan; J. Barbosa; J. Guiteras; J. L. Beltrn

2007-01-01

257

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  

USGS Publications Warehouse

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 of the calculated MRLs and MDLs and evaluation of the signal-to-noise ratios for each compound, the MRLs and MDLs are set at 0.010 and 0.003 ug/L, respectively, for all three compounds.

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

2007-01-01

258

Novel triphenylantimony(V) and triphenylbismuth(V) complexes with benzoic acid derivatives: structural characterization, in vitro antileishmanial and antibacterial activities and cytotoxicity against macrophages.  

PubMed

Two novel organoantimony(V) and two organobismuth(V) complexes of the type ML2 were synthesized, with L = acetylsalicylic acid (HL1) or 3-acetoxybenzoic acid (HL2) and M = triphenylantimony(V) (M1) or triphenylbismuth(V) (M2). Complexes, [M1(L1)2] (1), [M1(L2)2]?CHCl3 (2), [M2(L1)2], (3) and [M2(L2)2] (4), were characterized by elemental analysis, IR and NMR. Crystal structures of triphenylantimony(V) dicarboxylate complexes 1 and 2 were determined by single crystal X-ray diffraction. Structural analyses revealed that 1 and 2 adopt five-coordinated extremely distorted trigonal bipyramidal geometries, binding with three phenyl groups in the equatorial position and two deprotonated organic ligands (L) in the axial sites. The metal complexes, their metal salts and ligands were evaluated in vitro for their activities against Leishmania infantum and amazonensis promastigotes and Staphylococcus aureus and Pseudomonas aeruginosa bacteria. Both the metal complexes showed antileishmanial and antibacterial activities but the bismuth complexes were the most active. Intriguingly, complexation of organobismuth(V) salt reduced its activity against Leishmania, but increased it against bacteria. In vitro cytotoxic test of these complexes against murine macrophages showed that antimony(V) complexes were the least toxic. Considering the selectivity indexes, organoantimony(V) complexes emerge as the most promising antileishmanial agents and organobismuth(V) complex 3 as the best antibacterial agent. PMID:24824136

Islam, Arshad; Da Silva, Jeferson Gomes; Berbet, Filipe Moan; da Silva, Sydnei Magno; Rodrigues, Bernardo Lages; Beraldo, Heloisa; Melo, Maria Norma; Frzard, Frdric; Demicheli, Cynthia

2014-01-01

259

Tetra-?-benzoato-?4 O:O?;?3 O:O,O?;?3 O,O?:O?-bis-[(benzoato-?2 O,O?)(1,10-phenanthroline-?2 N,N?)terbium(III)] benzoic acid disolvate  

PubMed Central

The asymmetric unit of the title complex, [Tb2(C7H5O2)6(C12H8N2)2]2C7H6O2, consists of one-half of the complex molecule, which lies on a crystallographic inversion centre, and one benzoic acid solvent molecule. The two TbIII ions are linked by four bridging benzoate ions, with a Tb?Tb distance of 3.9280?(6)?. Additionally, each TbIII ion is coordinated by one phenanthroline heterocycle and a bidentate benzoate ion. The irregular nine-coordinated geometry of the TbIII ion is composed of seven O and two N atoms. The molecular structure is stabilized by intramolecular CH?O hydrogen bonds. In the crystal structure, molecules are linked into chains along the a axis by intermolecular CH?O hydrogen bonds. The crystal structure is further stabilized by intermolecular CH?O and CH?? interactions. Weak ?? interactions are also observed [centroidcentroid distances = 3.6275?(14)3.6604?(14)?].

Ooi, Ping Howe; Teoh, Siang Guan; Yeap, Chin Sing; Fun, Hoong-Kun

2010-01-01

260

A Novel Electrochemical Sensor for Probing Doxepin Created on a Glassy Carbon Electrode Modified with Poly(4-Amino- benzoic Acid)/Multi-Walled Carbon Nanotubes Composite Film  

PubMed Central

A novel electrochemical sensor for sensitive detection of doxepin was prepared, which was based on a glassy carbon electrode modified with poly(4-aminobenzoic acid)/multi-walled carbon nanotubes composite film [poly(4-ABA)/MWNTs/GCE]. The sensor was characterized by scanning electron microscopy and electrochemical methods. It was observed that poly(4-ABA)/MWNTs/GCE showed excellent preconcentration function and electrocatalytic activities towards doxepin. Under the selected conditions, the anodic peak current was linear to the logarithm of doxepin concentration in the range from 1.0 10?9 to 1.0 10?6 M, and the detection limit obtained was 1.0 10?10 M. The poly(4-ABA)/MWNTs/GCE was successfully applied in the measurement of doxepin in commercial pharmaceutical formulations, and the analytical accuracy was confirmed by comparison with a conventional ultraviolet spectrophotometry assay.

Xu, Xiao-Li; Huang, Fei; Zhou, Guo-Liang; Zhang, Song; Kong, Ji-Lie

2010-01-01

261

1,2-Bis(pyridin-4-yl)diazene-3,4,5-trihy-droxy-benzoic acid-methanol (3/2/2)  

PubMed Central

The title compound, 3C10H8N42C7H6O52CH4O, has a molecular crystal structure which results from the cocrystallization of gallic acid (GA), 4,4?-azodipyridine (AzPy) and methanol in a 2:3:2 molar ratio. The asymmetric unit comprises one molecule each of GA, AzPy and methanol in general positions and half a molecule of AzPy as this is located about a centre of inversion. In the crystal, all the components of the structure are associated via the extended system of hydrogen bonds (OH?O and OH?N) and ?? stacking interactions [centroidcentroid distance = 3.637?(3)?] into two-dimensional supramolecular layers which are packed parallel to the [101] plane. The shortest perpendicular distance and the slippage between aromatic groups are 3.395?(3) and 2.152?(3)?, respectively. The AzPy molecules display a trans conformation with respect to the azo groups.

Rusu, Elena; Shova, Sergiu; Rusu, Gheorghe

2012-01-01

262

2-[benzoyl(hydroxyimino)methylamino]benzoic acid.  

PubMed

The structure of the title compound, C(15)H(12)N(2)O(4), consists of a polymeric arrangement, around inversion centres, of molecules linked through O-H.N and O-H.O hydrogen bonds; there are also intramolecular hydrogen bonds. All these hydrogen-bond interactions result in the formation of infinite chains parallel to the [010] direction. The oxime group has an E conformation. PMID:15071230

Soylu, Serkan; Ta?, Murat; Bati, Hmeyra; Cali?kan, Nezihe; Bykgngr, Orhan

2004-04-01

263

Biosynthesis and metabolism of salicylic acid.  

PubMed Central

Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-beta-D-glucoside and methyl salicylate. Two key enzymes involved in SA biosynthesis and metabolism: benzoic acid 2-hydroxylase, which converts benzoic acid to SA, and UDPglucose:SA glucosyltransferase (EC 2.4.1.35), which catalyzes conversion of SA to SA glucoside have been partially purified and characterized. Progress in enzymology and molecular biology of SA biosynthesis and metabolism will provide a better understanding of signal transduction pathway involved in plant disease resistance.

Lee, H I; Leon, J; Raskin, I

1995-01-01

264

Biosynthesis and metabolism of salicylic acid  

SciTech Connect

Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-{beta}-D-glucoside and methyl salicylate. Two key enzymes involved in SA biosynthesis and metabolism: benzoic acid 2-hydroxylase, which converts benzoic acid to SA, and UDPglucose:SA glucosyltransferase (EC 2.4.1.35), which catalyzes conversion of SA to SA glucoside have been partially purified and characterized. Progress in enzymology and molecular biology of SA biosynthesis and metabolism will provide a better understanding of signal transduction pathway involved in plant disease resistance. 62 refs., 1 fig.

Lee, H.; Leon, J.; Raskin, I. [Rutgers Univ., New Brunswick, NJ (United States)

1995-05-09

265

Solid-phase extraction of acidic herbicides.  

PubMed

A discussion of solid-phase extraction method development for acidic herbicides is presented that reviews sample matrix modification, extraction sorbent selection, derivatization procedures for gas chromatographic analysis, and clean-up procedures for high-performance liquid chromatographic analysis. Acidic herbicides are families of compounds that include derivatives of phenol (dinoseb, dinoterb and pentachlorophenol), benzoic acid (acifluorfen, chloramben, dicamba, 3,5-dichlorobenzoic acid and dacthal--a dibenzoic acid derivative), acetic acid [2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)], propanoic acid [dichlorprop, fluazifop, haloxyfop, 2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP) and silvex], butanoic acid [4-(2,4-dichlorophenoxy)butanoic acid (2,4-DB) and 4-(4-chloro-2-methylphenoxy)butanoic acid (MCPB)], and other miscellaneous acids such as pyridinecarboxylic acid (picloram) and thiadiazine dioxide (bentazon). PMID:10941675

Wells, M J; Yu, L Z

2000-07-14

266

Amino acids  

MedlinePLUS

Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

267

Crystal and solution structures of di- n-butyltin(IV) complexes of 5-[( E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: En route to elegant self-assembly via modulation of the tin coordination geometry  

Microsoft Academic Search

Reactions of nBu2SnCl(L1) (1), where L1=acid residue of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol, with various substituted benzoic acids in refluxing toluene, in the presence of triethylamine, yielded dimeric mixed ligand di-n-butyltin(IV) complexes of composition [nBu2Sn(L1)(L26)]2 where L2=benzene carboxylate (2), L3=2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoate (3), L4=5-[(E)-2-(4-methylphenyl)-1-diazenyl]-2-hydroxybenzoate (4), L5=2-{(E)-4-hydroxy-3-[(E)-4-chlorophenyliminomethyl]-phenyldiazenyl}benzoate (5) and L6=2-[(E)-(3-formyl-4-hydroxyphenyl)-diazenyl]benzoate (6). All complexes (16) have been characterized by elemental analyses, IR, 1H, 13C and 117Sn NMR and

Tushar S. Basu Baul; Archana Mizar; Anup Paul; Giuseppe Ruisi; Rudolph Willem; Monique Biesemans; Anthony Linden

2009-01-01

268

The Biosynthesis of Salicylic Acid in Potato Plants1  

Microsoft Academic Search

Spraying potato (Solanum tuberosum L.) leaves with arachidonic acid (AA) at 1500 m gm L 21 led to a rapid local synthesis of salicylic acid (SA) and accumulation of a SA conjugate, which was shown to be 2-O-b-glucopyranosylsalicylic acid. Radiolabeling studies with untreated leaves showed that SA was synthesized from phenylala- nine and that both cinnamic and benzoic acid were

Jean-Luc Coquoz; Antony Buchala; Jean-Pierre Metraux

1998-01-01

269

Folic Acid  

MedlinePLUS

Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

270

Folic Acid  

MedlinePLUS

Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

271

Transcellular Transport of Benzole Acid Across Caco-2 Cells by a pH-Dependent and Carrier-Mediated Transport Mechanism  

Microsoft Academic Search

The pH-dependent transcellular transport of [14 C]benzoic acid across a Caco-2 cell monolayer is shown to be mediated by a monocarboxylic acid-specific carrier-mediated transport system, localized on the apical membrane. Evidence for the carrier-mediated transport of benzoic acid includes (a) the significant temperature and concentration dependence, (b) the metabolic energy dependence, (c) the inhibition by unlabeled benzoic acid and other

Akira Tsuji; Hitomi Takanaga; Ikumi Tamai; Tetsuya Terasaki

1994-01-01

272

FT-IR, Raman and DFT study of 2-amino-5-fluorobenzoic acid and its biological activity with other halogen (Cl, Br) substitution  

NASA Astrophysics Data System (ADS)

The Fourier-transform Raman and infrared spectra of 2-amino-5-fluoro benzoic acid has been recorded and analyzed. The optimized geometry of the other halogen substitution (Cl, Br) have been computed with the help of density functional theory. The detailed interpretation of vibrational spectra of 2-amino-5-fluoro benzoic acid have performed in terms of potential energy distribution analysis. Natural bond orbital analysis on 2-amino-5-fluoro benzoic acid, 2-amino-5-chloro benzoic acid and 2-amino-5-bromo benzoic acid has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. The p Ka values of 2-amino-5-fluoro benzoic acid, 2-amino-5-chloro benzoic acid and 2-amino-5-bromo benzoic acid are computed using MOPAC and it is related with HOMO-LUMO energy difference obtained from Gaussian 03 software. The biological activity of 2-amino-5-fluoro benzoic acid has been predicted based on these values. The inhibition activity of 2-amino-5-bromo benzoic acid with the protein tyrosine kinase 3LQ8 is simulated by using Autodock software.

Xavier, T. S.; Hubert, Joe I.

2011-07-01

273

Varieties in symmetry non-equivalent structural arrangements in solvates of 2-(3-methylene-1,3,7-trioxo-6-(2-carboxy-phenyl)-3,5,6,7-tetrahydro-1 H-pyrrolo[3,4- f]isoindol-2-yl)benzoic acid  

Microsoft Academic Search

The crystal structures of few solvates of 2-(3-methylene-1,3,7-trioxo-6-(2-carboxy-phenyl)-3,5,6,7-tetrahydro-1H-pyrrolo[3,4-f]isoindol-2-yl)benzoic acid (A) namely A4H2O;A2DMF; A2Py;A3Py are determined (where Py=pyridine, DMF=dimethylformamide). The crystal structure of the hydrated form has Z?=0.5, whereas other solvates with DMF and pyridine has Z?=1. The neighboring host molecules in the crystal lattices of these solvates have different orientations; these orientations are related by translation or translation cum rotation

Devendra Singh; Jubaraj B. Baruah

2009-01-01

274

Acid rain  

Microsoft Academic Search

Acid precipitation is a global problem. The effects were first seen in Europe; it affects the Great Lakes and the Midwest because higher-than-normal levels of acidity in rain are found in these areas. Several bays of the Great Lakes are now known to receive substantial runoff from freshwater streams that have been made acidic by acid rains. These areas may

1979-01-01

275

Biosynthesis and Metabolism of Salicylic Acid  

Microsoft Academic Search

Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-beta-D-glucoside and methyl salicylate.

Hyung-Il Lee; Jose Leon; Ilya Raskin

1995-01-01

276

Lactic Acid Fermentation of Vegetables - an Energy Conserving Technique Giving Tasty Products with Good Keeping Qualities.  

National Technical Information Service (NTIS)

Carrots, turnips and red beets have been fermented using lactic acid. The products have been tested regarding taste and keeping qualities. Some conserving additives are needed to eliminate development of yeast or mould fungi. Benzoic acid can be added wit...

R. Andersson

1986-01-01

277

Mefenamic Acid  

MedlinePLUS

Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain (pain that happens before or during a menstrual period). Mefenamic acid is in a class of medications called NSAIDs. ...

278

Aminocaproic Acid  

MedlinePLUS

Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

279

Ascorbic Acid  

MedlinePLUS

Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops ...

280

Shikimic Acid  

NSDL National Science Digital Library

The molecule for this month comes from the article Isolation of Shikimic Acid from Star Aniseed by Richard Payne and Michael Edmonds. Shikimic acid plays a key role in the biosynthesis of many important natural products including aromatic amino acids, alkaloids, phenolics, and phenylpropanoids. It plays such an important role that one of the key biosynthetic pathways is referred to as the shikimate pathway.

281

Synthesis, characterization and catalytic properties of diorganotin derivatives. Crystal and molecular structure of the first complex of 2-(2-methyl-3-nitroanilino)benzoic acid of 1,2:3,4-di-?2-2-(2-methyl-3-nitroanilino)benzoato- O, O-1,3-bis-2-(2-methyl-3-nitroanilino)benzoato- O-1,2,4:2,3,4-di-?3-oxo-tetrakis[di-methyltin(IV)  

Microsoft Academic Search

The complexes [Me2(MNAB)SnOSn(MNAB)Me2]2 (2) and [Me2Sn(MNAB)2] (3), where HMNAB is 2-(2-methyl-3-nitroanilino)benzoic acid, (1), have been prepared and structurally characterized by means of vibrational, 1H and 13C NMR spectroscopies. The crystal structure of [Me2(MNAB)SnOSn(MNAB)Me2]2 has been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement. The structure is centro-symmetric and features a central

Vaso N. Dokorou; Dimitra Kovala-Demertzi; Maria Louloudi; Anca Silvestru; Mavroudis A. Demertzis

2008-01-01

282

Direct and indirect reductive amination of aldehydes and ketones with solid acid-activated sodium borohydride under solvent-free conditions  

Microsoft Academic Search

A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride activated by boric acid, p-toluenesulfonic acid monohydrate or benzoic acid as reducing agent under solvent-free conditions is described.

Byung Tae Cho; Sang Kyu Kang

2005-01-01

283

Pathway of Salicylic Acid Biosynthesis in Healthy and Virus-Inoculated Tobacco.  

PubMed Central

Salicylic acid (SA) is a likely endogenous regulator of localized and systemic disease resistance in plants. During the hypersensitive response of Nicotiana tabacum L. cv Xanthi-nc to tobacco mosaic virus (TMV), SA levels rise dramatically. We studied SA biosynthesis in healthy and TMV-inoculated tobacco by monitoring the levels of SA and its likely precursors in extracts of leaves and cell suspensions. In TMV-inoculated leaves, stimulation of SA accumulation is accompanied by a corresponding increase in the levels of benzoic acid. 14C-Tracer studies with cell suspensions and mock-or TMV-inoculated leaves indicate that the label moves from trans-cinnamic acid to SA via benzoic acid. In healthy and TMV-inoculated tobacco leaves, benzoic acid induced SA accumulation. o-Coumaric acid, which was previously reported as a possible precursor of SA in other species, did not increase SA levels in tobacco. In healthy tobacco tissue, the specific activity of newly formed SA was equal to that of the supplied [14C]benzoic acid, whereas in TMV-inoculated leaves some isotope dilution was observed, presumably because of the increase in the pool of endogenous benzoic acid. We observed accumulation of pathogen-esis-related-1 proteins and increased resistance to TMV in benzoic acid- but not in o-coumaric acid-treated tobacco leaves. This is consistent with benzoic acid being the immediate precursor of SA. We conclude that in healthy and virus-inoculated tobacco, SA is formed from cinnamic acid via benzoic acid.

Yalpani, N.; Leon, J.; Lawton, M. A.; Raskin, I.

1993-01-01

284

Studies of the acidic components of the Colorado Green River formation oil shale-Mass spectrometric identification of the methyl esters of extractable acids.  

NASA Technical Reports Server (NTRS)

Study of solvent extractable acidic constituents of oil shale from the Colorado Green River Formation. Identification of individual components is based on gas chromatographic and mass spectrometric data obtained for their respective methyl esters. Normal acids, isoprenoidal acids, alpha, omega-dicarboxylic acids, mono-alpha-methyl dicarboxylic acids and methyl ketoacids were identified. In addition, the presence of monocyclic, benzoic, phenylalkanoic and naphthyl-carboxylic acids, as well as cycloaromatic acids, is demonstrated by partial identification.

Haug, P.; Schnoes, H. K.; Burlingame, A. L.

1971-01-01

285

Pyrolysis Mechanisms of Aromatic Carboxylic Acids  

SciTech Connect

Although decarboxylation of carboxylic acids is widely used in organic synthesis, there is limited mechanistic information on the uncatalyzed reaction pathways of aromatic carboxylic acids at 300-400 {degrees} C. The pyrolysis mechanisms of 1,2-(3,3-dicarboxyphenyl)ethane, 1,2-(4,4-dicarboxylphenyl)ethane, 1-(3-carboxyphenyl)-2-(4- biphenyl)ethane, and substituted benzoic acids have been investigated at 325-425 {degrees} C neat and diluted in an inert solvent. Decarboxylation is the dominant pyrolysis path. Arrhenius parameters, substituent effects, and deuterium isotope effects are consistent with decarboxylation by an electrophilic aromatic substitution reaction. Pyrolysis of benzoic acid in naphthalene, as a solvent, produces significant amounts of 1- and 2-phenylnaphthalenes. The mechanistic pathways for decarboxylation and arylation with be presented.

Britt, P.F.; Eskay, T.P.; Buchanan, A.C. III

1997-12-31

286

Identification of Lactic Acid Bacteria from Chili Bo, a Malaysian Food Ingredient  

Microsoft Academic Search

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28C with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg21 (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison

JRGEN J. LEISNER; BRUNO POT; HENRIK CHRISTENSEN; GULAM RUSUL; JOHN E. OLSEN; BEE WAH WEE; KHARIDAH MUHAMAD; HASANAH M. GHAZALI

1999-01-01

287

Biotransformation of gallic acid by Beauveria sulfurescens ATCC 7159  

Microsoft Academic Search

Preparative-scale fermentation of gallic acid (3,4,5-trihydroxybenzoic acid) (1) with Beauveria sulfurescens ATCC 7159 gave two new glucosidated compounds, 4-(3,4-dihydroxy-6-hydroxymethyl-5-methoxy-tetrahydro-pyran-2-yloxy)-3-hydroxy-5-methoxy-benzoic\\u000a acid (4), 3-hydroxy-4,5-dimethoxy-benzoic acid 3,4-dihydroxy-6-hydroxymethyl-5-methoxy-tetrahydro-pyran-2-yl ester (7), along with four known compounds, 3-O-methylgallic acid (2), 4-O-methylgallic acid (3), 3,4-O-dimethylgallic acid (5), and 3,5-O-dimethylgallic acid (6). The new metabolite genistein 7-O-?-D-4?-O-methyl-glucopyranoside (8) was also obtained as a byproduct due to the use

Feng-Lin Hsu; Li-Ming Yang; Shwu-Fen Chang; Li-Hsuan Wang; Chung-Yi Hsu; Pan-Chun Liu; Shwu-Jiuan Lin

2007-01-01

288

Basically Acids  

NSDL National Science Digital Library

Students learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.

University Of Houston

289

Acid clusters  

SciTech Connect

Molecular clusters can be considered to be the smallest size range of an aerosol particle size distribution. Nucleation from the gas phase to particles or droplets involves the formation of clusters in the initial stages. Consequently, knowledge of the properties and formation of clusters containing acids contribute to an understanding of acid rain. This paper presents an overview of results obtained in the laboratory on the formation and stability of both neutral and ionized acid clusters. With free jet expansion techniques, the authors have produced clusters of aqueous nitric acid, aqueous hydrochloric acid, aqueous sulfuric acid, acetic acid and aqueous sulfur dioxide. For analogy to buffering, the formation of clusters containing ammonia have also been examined. These have included ammonia with aqueous nitric acid, hydrogen sulfide and sulfur dioxide. The basic experiment involves expansion of vapor through a nozzle, collimation of the jet with a skimmer to form a well-directed molecular beam, and detection of clusters via electron impact ionization and mass spectrometry. Some variations include the introduction of a reactive gas into vacuum near the expansion as described elsewhere and the implementation of an electrostatic quadrupolar field to examine the polarity of the neutral clusters.

Keesee, R.G.; Castleman, A.W. Jr.

1986-04-01

290

Domoic Acid  

NSDL National Science Digital Library

This online student report discusses the chemistry of domoic acid, a biotoxin that is produced by the diatom Psuedo-nitzschia and associated with Amnesiac Shellfish Poisoning (ASP). In addition to a descriptive summary and images, the report links to other areas of interest related to domoic acid poisoning including signs and symptoms, modes of action, and treatment.

Bailey, Christina; Kohlen, Corinne

2010-02-10

291

Acid rain  

Microsoft Academic Search

The causes and effects of acid rain are detailed. Sulfur dioxide and nitrogen dioxide emissions from anthropogenic sources are the primary causative agents. These emissions are transported over long distances and transformed into sulfates and nitrates and washed out of the atmosphere. Trends in acidity in precipitation water are reviewed for eastern portions of Canada and the U.S. Adverse effects

R. E. Ghelardi; B. L. Murphy

2009-01-01

292

Acids (GCMP)  

NSDL National Science Digital Library

Acids: this is a resource in the collection "General Chemistry Multimedia Problems". We will observe the reaction of sodium bicarbonate with three acid solutions. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

293

Acid rain  

SciTech Connect

This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

Elsworth, S.

1985-01-01

294

Usnic acid.  

PubMed

Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that is commercially available. Usnic acid is uniquely found in lichens, and is especially abundant in genera such as Alectoria, Cladonia, Usnea, Lecanora, Ramalina and Evernia. Many lichens and extracts containing usnic acid have been utilized for medicinal, perfumery, cosmetic as well as ecological applications. Usnic acid as a pure substance has been formulated in creams, toothpaste, mouthwash, deodorants and sunscreen products, in some cases as an active principle, in others as a preservative. In addition to antimicrobial activity against human and plant pathogens, usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory and analgesic activity. Ecological effects, such as antigrowth, antiherbivore and anti-insect properties, have also been demonstrated. A difference in biological activity has in some cases been observed between the two enantiomeric forms of usnic acid. Recently health food supplements containing usnic acid have been promoted for use in weight reduction, with little scientific support. The emphasis of the current review is on the chemistry and biological activity of usnic acid and its derivatives in addition to rational and ecologically acceptable methods for provision of this natural compound on a large scale. PMID:12453567

Inglfsdttir, K

2002-12-01

295

Acid test  

NSDL National Science Digital Library

Baking soda can be used as an indicator of how much acid a substance contains. Lemons and limes have more acid in them than grapefruits and oranges. Indophenol can be used as an indicator of how much vitamin C is in a substance.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-06

296

Acid rain  

SciTech Connect

Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

Sweet, W.

1980-06-20

297

Effect of benzoate on microbial decomposition of fulvic acids in Tjeukemeer ( the Netherlands )  

Microsoft Academic Search

Abstrud The addition of benzoic acid to water from Tjeukemeer stimulated bacterial growth and decreased both the fluorescence and the color of the water, indicating disappearance of fulvic acids. This stimulation of bacterial growth is shown to result most likely from a priming effect of bcnzoic acid on the slow microbial decomposition of fulvic acid. During growth of an Arthrobucter

H. DE HAAN

1977-01-01

298

Acid Rain  

NSDL National Science Digital Library

Due to the presence of dissolved gases such as carbon dioxide, rainfall is naturally acidic. The release of other gases and chemicals such as sulfur dioxide during the combustion of coal and oil can cause rainfall to become even more acidic, sometimes to the point of toxicity. In this activity, students will measure the pH of local rainfall to see what effect these gases have in their region. They will also check an online resource to see how the releases of acid rain-causing chemicals have varied over the past 20 years, and answer questions about the information they uncover.

Fox, Chris

299

Folic Acid  

MedlinePLUS Videos and Cool Tools

... register. I'm interested in: Pregnancy Baby growth & care Research Volunteer opportunities Advocacy in government For health ... acid During your pregnancy Your pregnant body Prenatal care Eating and nutrition Physical activity Emotional and life ...

300

ACID RAIN  

EPA Science Inventory

Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

301

Phenylpropanoid Metabolism in Suspension Cultures of Vanilla planifolia Andr. : III. Conversion of 4-Methoxycinnamic Acids into 4-Hydroxybenzoic Acids.  

PubMed

Feeding of 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid and 3,4,5-trimethoxycinnamic acid to cell suspension cultures of Vanilla planifolia resulted in the formation of 4-hydroxybenzoic acid, vanillic acid, and syringic acid, respectively. The homologous 4-methoxybenzoic acids were demethylated to the same products. It is concluded that the side chain degrading enzyme system accepts the 4-methoxylated substrates while the demethylation occurs at the benzoic acid level. The demethylating enzyme is specific for the 4-position. Feeding of [O-(14)C-methyl]-3,4-dimethoxycinnamic acid revealed that the first step in the conversion is the glycosylation of the cinnamic acid to its glucose ester. A partial purification of a UDP-glucose: trans-cinnamic acid glucosyltransferase is reported. 4-Methoxy substituted cinnamic acids are better substrates for this enzyme than 4-hydroxy substituted cinnamic acid. It is suggested that 4-methoxy substituted cinnamic acids are intermediates in the biosynthetic conversion of cinnamic acids to benzoic acids in cells of V. planifolia. PMID:16667674

Funk, C; Brodelius, P E

1990-09-01

302

Methanogenic decomposition of ferulic acid, a model lignin derivative  

SciTech Connect

Ferulic acid, a model lignin derivative, was observed to be biodegradable to methane and carbon dioxide under strict anaerobic conditions. This conversion appears to be carried out by a consortium of bacteria similar to that previously described for the methanogenic degradation of benzoic acid. A temporary buildup of acetate in these cultures indicates that it is a likely intermediate and precursor for methane formation. An analog of coenzyme M, 2-bromoethanesulfonic acid (BESA), inhibited gas production and enhanced the buildup of propionate, butyrate, isobutyrate, and isovalerate. Phenylacetate, cinnamate, 3-phenylpropionate, benzoate, cyclohexane carboxylate, adipate, and pimelate were also detected in BESA-inhibited cultures. A pathway is proposed which includes these various acids as possible intermediates in the methanogenic degradation of ferulic acid. This model overlaps previously described benzoic acid degradation pathways, suggesting that this type of anaerobic degradation may be common for aromatic compounds.

Healy, J.B. Jr.; Young, L.Y.; Reinhard, M.

1980-02-01

303

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage?  

PubMed Central

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-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml?1 for two of the three test organisms).

Broberg, Anders; Jacobsson, Karin; Strom, Katrin; Schnurer, Johan

2007-01-01

304

Acid Stomach  

NSDL National Science Digital Library

This Science NetLinks lesson is intended for a high-school, introductory chemistry class or health class. The lesson begins with an article on the history of the development of aspirin. Students will then complete a lab that compares the reaction of regular aspirin, buffered aspirin, and enteric aspirin in neutral, acidic, and basic solutions. They will then analyze the results of the experiment to gain insight into how this information was used by researchers to solve some of the problems associated with aspirin. To complete the lesson, students must understand acids and bases.

Science Netlinks;

2003-08-07

305

Salicylic acids  

PubMed Central

Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here.

Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

2012-01-01

306

Ethenzamide-gentisic acid-acetic acid (2/1/1)  

PubMed Central

In the title co-crystal solvate, 2-ethoxybenzamide2,5-dihydroxybenzoic acidethanoic acid (2/1/1), 2C9H11NO2C7H6O4C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxybenzamide) and gentisic acid (systematic name: 2,5-dihydroxybenzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component molecular assembly held together by NH?O and OH?O hydrogen bonds. This assembly features two symmetry-independent molecules of ethenzamide, forming supramolecular acidamide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong OH?O [O?O = 2.5446?(15) and 2.5327?(15)?] and less strong NH?O [N?O = 2.9550?(17) and 2.9542?(17)?] hydrogen bonds. The overall crystal packing features several CH?O and ?? stacking interactions [centroidcentroid distance = 3.7792?(11)?].

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B.H.

2010-01-01

307

Stearic Acid  

ERIC Educational Resources Information Center

A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

Young, Jay A.

2004-01-01

308

Amino Acids  

NSDL National Science Digital Library

The Featured Molecules this month are the 20 standard α-amino acids found in proteins and serve as background to the paper by Barone and Schmidt on the Nonfood Applications of Proteinaceous Renewable Materials. The molecules are presented in two formats, the neutral form and the ionized form found in solution at physiologic pH.

309

Ethacrynic Acid  

MedlinePLUS

... or any of the ingredients in ethacrynic acid tablets. Ask your doctor or pharmacist for a list of the ingredients.tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements and herbal products you are taking or plan to take. ...

310

Tranexamic Acid  

MedlinePLUS

... or any of the ingredients in tranexamic acid tablets. Ask your pharmacist for a list of the ingredients.tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. ...

311

Carbonate acidizing  

SciTech Connect

The authors present the first quantitative study and complete model of the wormholing phenomenon, leading to a means of predicting and optimizing carbonate acidizing treatments. Laboratory experiments on a gypsum model system and computer simulations show that for a given geometry, wormholes can be quantified by a unique parameter, their equivalent hydraulic length. The behavior of this quantifying parameter vs. all the system parameters is studied and allows the quantitative prediction of the efficiency of an acidizing treatment. This study highlights the fractal nature of the phenomenon, which is accounted for in the equations, and the strong effect of the sample geometry. Three types of etching can be obtained: compact, wormhole type, or homogeneous. The optimum conditions for achieving the best skin decrease correspond to the creation of wormholes and can then be defined in terms of fluid reactivity and injection rate.

Daccord, G.; Touboul, E.; Lenormand, R.

1989-02-01

312

Levulinic acid  

PubMed Central

The title compound (systematic name: 4-oxopentanoic acid), C5H8O3, is close to planar (r.m.s. deviation = 0.0762?). In the crystal, the molecules interact via OH?O hydrogen bonds in which the hydroxy O atoms act as donors and the ketone O atoms in adjacent molecules as acceptors, forming C(7) chains along [20-1].

Hachula, Barbara; Polasz, Anna; Dzida, Marzena; Nowak, Maria; Kusz, Joachim

2013-01-01

313

Domoic Acid  

NSDL National Science Digital Library

This highly detailed chemical information page features domoic acid, a toxin associated with Amnesic shellfish poisoning and naturally produced by the red algae Chondria armata and diatoms of the genus Pseudo-nitzschia. Created by the International Programme on Chemical Safety, this web page organizes information under the following sections: Name, Summary, Physio-Chemical Properties, Uses, Routes of Entry, Kinetics, Toxicology, Toxicological and Biomedical Investigations, Clinical Effects, Management, Illustrative Cases, Additional Information, References, and Authors.

Inchem; Safety, International P.

314

Dynamics of phenolic acids and lignin accumulation in metal-treated Matricaria chamomilla roots  

Microsoft Academic Search

Phenylalanine ammonia-lyase (PAL) activity, 11 phenolic acids and lignin accumulation in Matricaria chamomilla roots exposed to low (3?M) and high (60 and 120?M) levels of cadmium (Cd) or copper (Cu) for 7days were investigated.\\u000a Five derivatives of cinnamic acid (chlorogenic, p-coumaric, caffeic, ferulic and sinapic acids) and six derivatives of benzoic acid (protocatechuic, vanillic, syringic, p-hydroxybenzoic, salicylic acids and protocatechuic

Jozef Kov?ik; Bo?ivoj Klejdus

2008-01-01

315

Comparative detoxication. The detoxication of aromatic acids by invertebrates: detection of agmatine conjugates in scorpions.  

PubMed

1. Benzoic acid and p-nitrobenzoic acid were converted in the scorpion Palamnaeus into N(1)-benzoylagmatine and N(1)-p-nitrobenzoylagmatine. 2. Some benzoyl- and p-nitrobenzoyl-arginine were also formed and these compounds were probable precursors of the agmatine derivatives. 3. p-Nitrobenzoyl- and p-aminobenzoyl-arginine were formed in millipedes dosed with the aromatic acids. 4. Woodlice excreted p-amino- and p-nitro-benzoic acid as their glycine conjugates and no conjugation could be found in the crab Gecarcinus and a freshwater crayfish Astacus. PMID:5911522

Hitchcock, M; Smith, J N

1966-03-01

316

Comparative detoxication. The detoxication of aromatic acids by invertebrates: detection of agmatine conjugates in scorpions  

PubMed Central

1. Benzoic acid and p-nitrobenzoic acid were converted in the scorpion Palamnaeus into N1-benzoylagmatine and N1-p-nitrobenzoylagmatine. 2. Some benzoyl- and p-nitrobenzoyl-arginine were also formed and these compounds were probable precursors of the agmatine derivatives. 3. p-Nitrobenzoyl- and p-aminobenzoyl-arginine were formed in millipedes dosed with the aromatic acids. 4. Woodlice excreted p-amino- and p-nitro-benzoic acid as their glycine conjugates and no conjugation could be found in the crab Gecarcinus and a freshwater crayfish Astacus.

Hitchcock, Margaret; Smith, J. N.

1966-01-01

317

Uptake of phenoxyacetic acid derivatives into Caco-2 cells by the monocarboxylic acid transporters.  

PubMed

The uptake mechanism of phenoxyacetic acid (PA) and its chlorine derivatives, 4-chlorophenoxyacetic acid (4-CPA), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), was investigated using Caco-2 cells. The cells were incubated with PA, 4-CPA, 2,4-D or 2,4,5-T at pH 6.0 and 37 degrees C. The order of uptake and lipophilicity expressed by n-octanol partition coefficients were PA<4-CPA<2,4-D<2,4,5-T. Incubation at 4 degrees C or at pH 7.4 significantly decreased these uptake. Furthermore, pretreatment with the protonophore, carbonylcyanide-p-(trifluoromethoxy) phenylhydrazone, or coincubation with benzoic acid, a typical substrate for the proton-linked monocarboxylic acid transporters (MCTs), significantly decreased the uptake of all compounds. The initial uptake rates of all compounds except PA were apparently saturable, suggesting the involvement of a carrier-mediated process. The order of uptake clearance of the compounds was the same as the order of their uptake and lipophilicity. Preloading of cells with benzoic acid significantly increased their uptake except for PA. These results suggest that the uptake of PA, 4-CPA, 2,4-D and 2,4,5-T from the apical membrane of Caco-2 cells is mediated via common MCTs shared, at least in part, with benzoic acid, and the increase in lipophilicity due to the chlor-substitution may increase uptake via the MCTs. PMID:19465094

Kimura, Osamu; Tsukagoshi, Kensuke; Endo, Tetsuya

2009-09-10

318

Acid Ocean  

NSDL National Science Digital Library

The I2I-Acid Ocean virtual lab is an e-learning activity where students become virtual scientists studying the impact of ocean acidification on sea urchin larval growth. Students recreate a real, up-to-date climate change experiment. They also learn important general scientific principles, such as the importance of sample size and numbers of replicates, and discuss what this research into a specific impact of climate change may mean for the future of our oceans. There is a French translation available.

319

Methylmalonic acid blood test  

MedlinePLUS

... acid is a substance produced when proteins (called amino acids) in the body break down. A test can ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

320

Folic acid - test  

MedlinePLUS

Folic acid is a type of B vitamin. This article discusses the test to measure the amount of folic acid in the blood. ... that may interfere with test results, including folic acid supplements. Drugs that can decrease folic acid measurements ...

321

3,5-Bis(benz-yloxy)benzoic acid  

PubMed Central

In the title compound, C21H18O4, the outer benzyl rings are disordered over two resolved positions in a 0.50 ratio. The OCH2 groups form dihedral angles of 4.1?(2) and 10.9?(4) with the central benzene ring, adopting a synanti conformation with respect to this ring. In the crystal, the molecules are linked by OH?O hydrogen bonds and weak CH?O interactions, forming chains along [010].

Moreno-Fuquen, Rodolfo; Grande, Carlos; Advincula, Rigoberto C.; Tenorio, Juan C.; Ellena, Javier

2012-01-01

322

3,5-Bis(benz-yloxy)benzoic acid.  

PubMed

In the title compound, C(21)H(18)O(4), the outer benzyl rings are disordered over two resolved positions in a 0.50 ratio. The O-CH(2) groups form dihedral angles of 4.1?(2) and 10.9?(4) with the central benzene ring, adopting a syn-anti conformation with respect to this ring. In the crystal, the mol-ecules are linked by O-H?O hydrogen bonds and weak C-H?O inter-actions, forming chains along [010]. PMID:23284545

Moreno-Fuquen, Rodolfo; Grande, Carlos; Advincula, Rigoberto C; Tenorio, Juan C; Ellena, Javier

2012-11-01

323

2-Methyl-3,5-dinitro-benzoic acid  

PubMed Central

In the title compound, C8H6N2O6, the O atoms of the nitro groups, the methyl H atoms and the carboxyl C=O and COH groups are disordered over two sets of sites with an occupancy ratio of 0.595?(16):0.405?(16). In the crystal, inversion dimers linked by pairs of OH?O hydrogen bonds arise for both carboxyl disorder components and CH?O bonds and weak CH?? interactions consolidate the packing.

Tahir, M. Nawaz; Raza, Abdul Rauf; Saddiqa, Aisha; Danish, Muhammad; Saleem, Iram

2009-01-01

324

4-(4-Octyloxybenzo-yloxy)benzoic acid  

PubMed Central

The title compound, C22H26O5, is an important intermediate for the synthesis of side-chain ligands for polymeric liquid crystals. The octyl group is coplanar with the central C6O moiety, where the maximum deviation of a C atom in the octyl group from the C6O plane is 0.161?(5)?. The crystal structure is stabilized by intermolecular OH?O hydrogen bonds.

Muhammad, Khushi; Khawar Rauf, M.; Ebihara, Masahiro; Hameed, Shahid

2009-01-01

325

HEALTH AND ENVIRONMENTAL EFFECTS DOCUMENT FOR BENZOIC ACID  

EPA Science Inventory

Health and Environmental Effects Documents (HEEDS) are prepared for the Office of Solid Waste and Emergency Response (OSWER). his document series is intended to support listings under the Resource Conservation and Recovery Act (RCRA) as well as to provide health-related limits an...

326

Benzoic acid glucosinolate esters and other glucosinolates from Arabidopsis thaliana  

Microsoft Academic Search

The spectacular recent progress in Arabidopsis thaliana molecular genetics furnishes outstanding tools for studying the formation and function of all metabolites in this cruciferous species. One of the major groups of secondary metabolites in A. thaliana is the glucosinolates. These hydrophilic, sulfur-rich glycosides appear to serve as defenses against some generalist herbivores and pathogens, and as feeding and oviposition stimulants

Michael Reichelt; Paul D Brown; Bernd Schneider; Neil J Oldham; Einar Stauber; Jim Tokuhisa; Daniel J Kliebenstein; Thomas Mitchell-Olds; Jonathan Gershenzon

2002-01-01

327

C7H6O2 Benzoic acid  

NASA Astrophysics Data System (ADS)

This document is part of Part 3 of Subvolume D `Asymmetric Top Molecules' of Volume 29 `Molecular Constants Mostly from Microwave, Molecular Beam, and Sub-Doppler Laser Spectroscopy' of Landolt-Brnstein - Group II `Molecules and Radicals'.

Vogt, J.

328

Hydrogen Peroxide Stimulates Salicylic Acid Biosynthesis in Tobacco  

Microsoft Academic Search

Hydrogen peroxide induced the accumulation of free benzoic acid (BA) and salicylic acid (SA) in tobacco (Nicotiana fabacum L. cv Xanthi-nc) leaves. Six hours after infiltration with 300 mM H202, the levels of BA and SA in leaves increased 5-fold over the levels detected in control leaves. The accumulation of BA and SA was preceded by the rapid activation of

Jos Len; Michael A. Lawton

329

New method of acidizing or acid fracturing: crosslinked acid gels  

SciTech Connect

Acid polymer gels having pH less than one have been crosslinked for retarding the chemical and physical activity of hydrochloric acid on calcareous formations. Hydrochloric acid concentrations from .0025 to 28% have been successfully crosslinked. This stimulation fluid offers high viscosity with adequate shear stability, perfect support for proppants, and clay stabilization. Additionally, the fluid provides effective fluid loss control and retardation of acid reaction enabling live acid to penetrate deeper into the formation for better formation conductivity and practically a residue-free break for rapid clean-up of the well after the job. Results of lab and field tests show the acid crosslinked system to be an effective stimulation fluid for acidizing and acid fracturing in calcareous and sandstone formations having low formation permeability.

Pabley, A.S.; Holcomb, D.L.

1980-01-01

330

Phenolic acids content, antioxidant and antimicrobial activity of Ligusticum mutellina L  

Microsoft Academic Search

A simple HPLC method has been used for separation and quantitative analysis of the phenolic acids in the methanolic extracts of Ligusticum mutellina aerial parts. Chlorogenic acid was the predominant phenolic acid. Additionally, gallic, p-OH-benzoic, caffeic, p-coumaric and ferulic acids were identified. Moderate antibacterial and antifungal activity (MIC?=?1.252.5?mg?mL) was observed for the methanol extract of L. mutellina herb received from

Elwira Sieniawska; Tomasz Baj; Renata Los; Krystyna Skalicka-Wozniak; Anna Malm; Kazimierz Glowniak

2012-01-01

331

Micellar acid-base potentiometric titrations of weak acidic and/or insoluble drugs.  

PubMed

The effect of various surfactants [the cationics cetyl trimethyl ammonium bromide (CTAB) and cetyl pyridinium chloride (CPC), the anionic sodium dodecyl sulphate (SDS), and the nonionic polysorbate 80 (Tween 80)] on the solubility and ionization constant of some sparingly soluble weak acids of pharmaceutical interest was studied. Benzoic acid (and its 3-methyl-, 3-nitro-, and 4-tert-butyl-derivatives), acetylsalicylic acid, naproxen and iopanoic acid were chosen as model examples. Precise and accurate acid-base titrations in micellar systems were made feasible using a microcomputer-controlled titrator. The response curve, response time and potential drift of the glass electrode in the micellar systems were examined. The cationics CTAB and CPC were found to increase considerably the ionization constant of the weak acids (delta pKa ranged from -0.21 to -3.57), while the anionic SDS showed negligible effect and the nonionic Tween 80 generally decreased the ionization constants. The solubility of the acids in aqueous micellar and acidified micellar solutions was studied spectrophotometrically and it was found increased in all cases. Acetylsalicylic acid, naproxen, benzoic acid and iopanoic acid could be easily determined in raw material and some of them in pharmaceutical preparations by direct titration in CTAB-micellar system instead of using the traditional non-aqueous or back titrimetry. Precisions of 0.3-4.3% RSD and good correlation with the official tedious methods were obtained. The interference study of some excipients showed that a preliminary test should be carried out before the assay of formulations. PMID:8466957

Gerakis, A M; Koupparis, M A; Efstathiou, C E

1993-01-01

332

Aromatic carbozylic acids isolated from the Colorado Green River Formation (Eocene)  

Microsoft Academic Search

Several series of aromatic carboxylic acids (including mono-, di-, and trimethyl benzoic; mono-, di-, and trimethyl propanoio; mono- and dimethyl butanoic; indanoic and tetrahydronaphthoic; and naphthoic acids) have been isolated from the extract of Colorado Green River Shale. Gas liquid chromatographic and both low and high resolution mass spectrometric techniques were utilized for separation and characterization respectively.

Pat Haug; H. K. Schnoes; A. L. Burlingame

1968-01-01

333

Direct hydrogenation of aromatic carboxylic acids to their corresponding aldehydes with zinc oxide catalysts  

Microsoft Academic Search

High yields of aromatic aldehydes were obtained by direct hydrogenation of aromatic carboxylic acids over different zinc oxide catalysts having distinctive surface properties. The reaction is carried out in a fixed bed reactor in gas phase at 330350C. High selectivity of 96% of benzaldehyde at 100% conversion of benzoic acid was achieved using a zinc oxide catalyst having very weakly

W. F. Hlderich; J. Tjoe

1999-01-01

334

Rapid acid hydrolysis of 5-aryl-3-(?-thiomorpholinoethyl)-1,2,4-oxadiazoles  

Microsoft Academic Search

The acid hydrolysis of a series of 5-aryl-3-(?-thiomorpholinoethyl)-1,2,4-oxadiazoles gave substituted benzoic acids and 2-amino-8-thia-1-aza-5-azoniaspiro[4.5]dec-1-ene\\u000a chloride hydrate, whose structure was demonstrated by spectral methods and X-ray diffraction structural analysis.

L. A. Kayukova; M. A. Orazbaeva; G. I. Gapparova; K. M. Beketov; A. A. Espenbetov; M. F. Faskhutdinov; B. T. Tashkhodjaev

2010-01-01

335

Automobiles and acid rain  

Microsoft Academic Search

In his editorial Acid rain Philip H. Abelson writes that everyone who drives an automobile is a contributor to acid rain. Examination of emissions data indicates that controlling automobile emissions will contribute little to solving acid precipitation problems. Of the strong acid anions associated with precipitation acidity, sulfate accounts for about 60% and nitrate for about 40%, on an equivalence

Hendrey

1985-01-01

336

Use of water and EDTA extractions to estimate available (free and reversibly bound) phenolic acids in Cecil soils  

Microsoft Academic Search

Sterile and microbe reinfested Cecil Ap and Bt soil materials amended with 0 to 5 mol\\/g of ferulic acid,p-coumaric acid,p-hydroxybenzoic acid, or vanillic acid were extracted after varying time intervals with water, EDTA, or NaOH to characterize sorption of cinnamic and benzoic acid derivatives and to determine the effectiveness of water and EDTA extractions in estimating concentrations of free and

U. Blum; A. D. Worsham; L. D. King; T. M. Gerig

1994-01-01

337

Comparative study on nano-crystalline titanium dioxide catalyzed photocatalytic degradation of aromatic carboxylic acids in aqueous medium  

Microsoft Academic Search

The comparative study on titanium dioxide (TiO2) catalyzed photocatalytic degradation (PCD) of aqueous aromatic carboxylic acids (phthalic acid, o-nitrobenzoic acid, o-chlorobenzoic acid and benzoic acid) was carried out in the presence of UV radiation using air. The TiO2 catalyst, synthesized by solgel technique and calcined at 673K, resulted ca. 100% anatase phase with 23nm crystallite size and surface area of

V. G. Gandhi; M. K. Mishra; M. S. Rao; A. Kumar; P. A. Joshi; D. O. Shah

2011-01-01

338

Folic Acid and Pregnancy  

MedlinePLUS

... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ... well as tissue formation. Continue Getting Enough Folic Acid The Centers for Disease Control and Prevention (CDC) ...

339

Acid Lipase Disease  

MedlinePLUS

NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage Disease, Wolmans Disease Table of Contents (click to jump ... research is being done? Clinical Trials What is Acid Lipase Disease ? Acid lipase disease occurs when the ...

340

Uric acid test (image)  

MedlinePLUS

Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... for testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

341

Organic acids tunably catalyze carbonic Acid decomposition.  

PubMed

Density functional theory calculations predict that the gas-phase decomposition of carbonic acid, a high-energy, 1,3-hydrogen atom transfer reaction, can be catalyzed by a monocarboxylic acid or a dicarboxylic acid, including carbonic acid itself. Carboxylic acids are found to be more effective catalysts than water. Among the carboxylic acids, the monocarboxylic acids outperform the dicarboxylic ones wherein the presence of an intramolecular hydrogen bond hampers the hydrogen transfer. Further, the calculations reveal a direct correlation between the catalytic activity of a monocarboxylic acid and its pKa, in contrast to prior assumptions about carboxylic-acid-catalyzed hydrogen-transfer reactions. The catalytic efficacy of a dicarboxylic acid, on the other hand, is significantly affected by the strength of an intramolecular hydrogen bond. Transition-state theory estimates indicate that effective rate constants for the acid-catalyzed decomposition are four orders-of-magnitude larger than those for the water-catalyzed reaction. These results offer new insights into the determinants of general acid catalysis with potentially broad implications. PMID:24933150

Kumar, Manoj; Busch, Daryle H; Subramaniam, Bala; Thompson, Ward H

2014-07-10

342

Acidic organic compounds in beverage, food, and feed production.  

PubMed

: Organic acids and their derivatives are frequently used in beverage, food, and feed production. Acidic additives may act as buffers to regulate acidity, antioxidants, preservatives, flavor enhancers, and sequestrants. Beneficial effects on animal health and growth performance have been observed when using acidic substances as feed additives. Organic acids could be classified in groups according to their chemical structure. Each group of organic acids has its own specific properties and is used for different applications. Organic acids with low molecular weight (e.g. acetic acid, lactic acid, and citric acid), which are part of the primary metabolism, are often produced by fermentation. Others are produced more economically by chemical synthesis based on petrochemical raw materials on an industrial scale (e.g. formic acid, propionic and benzoic acid). Biotechnology-based production is of interest due to legislation, consumer demand for natural ingredients, and increasing environmental awareness. In the United States, for example, biocatalytically produced esters for food applications can be labeled as "natural," whereas identical conventional acid catalyst-based molecules cannot. Natural esters command a price several times that of non-natural esters. Biotechnological routes need to be optimized regarding raw materials and yield, microorganisms, and recovery methods. New bioprocesses are being developed for organic acids, which are at this time commercially produced by chemical synthesis. Moreover, new organic acids that could be produced with biotechnological methods are under investigation for food applications. PMID:24275825

Quitmann, Hendrich; Fan, Rong; Czermak, Peter

2014-01-01

343

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

PubMed Central

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. 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.

Diakogiannis, Ioannis; Berberi, Anita; Siapi, Eleni; Arkoudi-Vafea, Angeliki; Giannopoulou, Lydia; Mastronicolis, Sofia K.

2013-01-01

344

Direct preparation of nitriles from carboxylic acids in continuous flow.  

PubMed

A continuous-flow protocol for the preparation of organic nitriles from carboxylic acids has been developed. The method is based on the acid-nitrile exchange reaction with acetonitrile, used as the solvent, and takes place without any catalyst or additives under the high-temperature/high-pressure conditions employed. At 350 C and 65 bar, where acetonitrile is in its supercritical state, the transformation of benzoic acid to benzonitrile requires 25 min. The protocol has been tested for a variety of nitriles, including aromatic and aliphatic substrates. PMID:24066706

Cantillo, David; Kappe, C Oliver

2013-10-18

345

Field enhancement sample stacking for analysis of organic acids in traditional Chinese medicine by capillary electrophoresis.  

PubMed

A technique known as field enhancement sample stacking (FESS) and capillary electrophoresis (CE) separation has been developed to analyze and detect organic acids in the three traditional Chinese medicines (such as Portulaca oleracea L., Crataegus pinnatifida and Aloe vera L.). In FESS, a reverse electrode polarity-stacking mode (REPSM) was applied as on-line preconcentration strategy. Under the optimized condition, the baseline separation of eight organic acids (linolenic acid, lauric acid, p-coumaric acid, ascorbic acid, benzoic acid, caffeic acid, succinic acid and fumaric acid) could be achieved within 20 min. Validation parameters of this method (such as detection limits, linearity and precision) were also evaluated. The detection limits ranged from 0.4 to 60 ng/mL. The results indicated that the proposed method was effective for the separation of mixtures of organic acids. Satisfactory recoveries were also obtained in the analysis of these organic acids in the above traditional Chinese medicine samples. PMID:22381886

Zhu, Qianqian; Xu, Xueqin; Huang, Yuanyuan; Xu, Liangjun; Chen, Guonan

2012-07-13

346

Acid Rain Study Guide.  

ERIC Educational Resources Information Center

Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid

Hunger, Carolyn; And Others

347

Acid-Base Equilibria  

NSDL National Science Digital Library

This 9-page PDF document is part of an environmental geochemistry course taught by Dr. David Sherman at the University of Bristol. Topics include acid-base theories, aqueous systems, strong and weak acids and bases, acid-base properties of minerals, the pH of weak acid and buffered systems, and the calculation of titration curves.

Sherman, David W.; Bristol, University O.

348

Syntheses of ?-resorcylic acid derivatives, novel potato micro-tuber inducing substances isolated from Lasiodiplodia theobromae  

Microsoft Academic Search

The syntheses of ?-resorcylic acid derivatives 1 and 2, isolated from fungus Lasiodiplodia theobromae, and their dimethyl ethers were accomplished. (R)-(?)-1,3-Butanediol was used as a chiral source of the side chain C6-synthon. The dianion of the benzoic acid moiety was alkylated with C6-bromide to give the desired skeleton. Several ?-resorcylic acid derivatives including 1 and 2 were synthesized via hydrogenation,

Qing Yang; Hiroaki Toshima; Teruhiko Yoshihara

2001-01-01

349

Inhibition of polygalacturonase and polygalacturonic acid lyase from Erwinia carotovora subsp. carotovora by phenolics in vitro  

Microsoft Academic Search

SummaryThe phenolic acids benzoic, caffeic, chlorogenic, ferulic, p-coumaric, protocatechuic, salicylic, sinapic, syringic and vanillic\\u000a together with vanillin, were tested for their ability to inhibit polygalacturonic acid lyase (PL) and polygalacturonase (PG)\\u000a in culture filtrates ofErwinia carotovora subsp.carotovora. None of the compounds inhibited PL at 200 ?g\\/ml, although syringic and sinapic acids caused a 54% and 43% reduction respectively\\u000a at 400

G. D. Lyon; Fiona M. McGill

1989-01-01

350

Acid tolerance in amphibians  

SciTech Connect

Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

Pierce, B.A.

1985-04-01

351

Chromatographic separations of aromatic carboxylic acids.  

PubMed

The purpose of this review is to present methods of chromatographic analysis of aromatic carboxylic acids. The separation, identification and quantitative analysis of aromatic carboxylic acids are necessary because of their importance as non-steroid antiphlogistic drugs, semi-products of biosynthesis of aromatic amino-acids in plants (phenolic acids), metabolites of numerous toxic substances, drugs and catecholamines. HPLC separation of ionic samples tends to be more complicated than separation of non-ionic compounds. The review describes the dependence of the retention of ionic solutes on pH and solvent composition as well as on the ionic strength of a mobile phase. The application of the ion-suppressing RP-HPLC method using organic modifiers (aqueous buffer solutions) as eluents in aromatic carboxylic acid analysis is also presented. In more difficult cases of analysis the addition of an ion-pairing reagent, such as the quaternary alkylammonium ion, is necessary to obtain satisfactory separations. Hypotheses of ion-pair formation in reversed-phase systems as well as the influence of various agents on the separation of ionic solutes in IP-RP systems are explained. Examples of the application of ion-pair liquid chromatography to the analysis of aromatic carboxylic acids have also been reviewed. The principles and application of ion-exchange chromatography to the purification, isolation and less frequently, to chromatographic analysis are discussed. Polar adsorbents and polar bonded stationary phases are also widely used in carboxylic acid separation in normal-phase systems, mainly by TLC, often coupled with densitometry. The review also shows examples of separation of chiral benzoic acids and their derivatives in LC systems. The possibilities of application of gas chromatography preceded by derivatisation or pyrolysis of acidic compounds and applications of GC-MS and Py-GC-MS coupled methods in identification and quantitation of aromatic carboxylic acids is also reviewed. PMID:9832241

Waksmundzka-Hajnos, M

1998-10-01

352

Gas-phase Acidities of Aspartic Acid, Glutamic Acid, and their Amino Acid Amides.  

SciTech Connect

Gas-phase acidities (GA or ?Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkages importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 34 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2? group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

Li, Zhong; Matus, Myrna H.; Velazquez, Hector A.; Dixon, David A.; Cassady, Carolyn J.

2007-02-14

353

Gas-phase acidities of aspartic acid, glutamic acid, and their amino acid amides  

NASA Astrophysics Data System (ADS)

Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

Li, Zhong; Matus, Myrna H.; Velazquez, Hector Adam; Dixon, David A.; Cassady, Carolyn J.

2007-09-01

354

Modulating the acidity: highly acidic Brnsted acids in asymmetric catalysis.  

PubMed

Recently, chiral highly acidic Brnsted acids have emerged as powerful catalysts for enantioselective C-C and C-X bond-forming reactions. Their strong acidity renders them valuable tools for the activation of imines, carbonyl compounds, and other weakly basic substrates. As a result, new perspectives are opened and highly stereoselective transformations based on the concept of chiral contact-ion-pair catalysis can be realized. This Minireview gives an overview of the design and application of these new organocatalysts and presents recent results in this rapidly growing field. PMID:21678531

Rueping, Magnus; Nachtsheim, Boris J; Ieawsuwan, Winai; Atodiresei, Iuliana

2011-07-18

355

40 CFR 704.33 - P-tert-butylbenzoic acid (P-TBBA), p-tert-butyltoluene (P-TBT) and p-tert-butylbenzaldehyde (P-TBB).  

Code of Federal Regulations, 2013 CFR

...33 P-tert-butylbenzoic acid (P-TBBA), p-tert-butyltoluene...substance p-tert-butylbenzoic acid, also identified as 4-(1,1-dimethylethyl)benzoic acid, CAS No. 98-73-7. ...address, and office telephone number (including area code) of...

2013-07-01

356

Theophylline-gentisic acid (1/1)  

PubMed Central

In the title 1:1 cocrystal, C7H8N4O2C7H6O4, the anti-asthmatic drug theophylline (systematic name: 1,3-dimethyl-7H-purine-2,6-dione) and a non-steroidal anti-inflammatory drug, gentisic acid (systematic name: 2,5-dihydroxybenzoic acid) crystallize together, forming two-dimensional hydrogen-bonded sheets involving NH?O and OH?N hydrogen bonds. The overall crystal packing features ?? stacking interactions [centroidcentroid distance = 3.348?(1)?]. The cocrystal described herein belongs to the class of pharmaceutical cocrystals involving two active pharmaceutical ingredients which has been relatively unexplored to date.

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B. H.

2009-01-01

357

Thin-Layer Separation of Citric Acid Cycle Intermediates, Lactic Acid, and the Amino Acid Taurine.  

National Technical Information Service (NTIS)

This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric ...

R. T. Riley M. C. Mix

1979-01-01

358

Simultaneous gas chromatographic quantitation of sugars and acids in citrus fruits, pears, bananas, grapes, apples and tomatoes  

Microsoft Academic Search

SummaryThe simultaneous quantitation of organic acids (glycolic, lactic, oxalic, sorbic, benzoic, succinic, malic, pimelic, tartaric, citric+isocitric, quinic, ascorbic, palmitic, caffeic, linoleic, stearic, arachidic, behenic, and chlorogenic acids), mannitol, sorbitol and sugars (arabinose, xylose, rhamnose, fructose, galactose, mannose, glucose, sucrose, maltose, isomaltose, raffinose and maltotriose) are reported. Optimum conditions for simultaneous silylation and quantitation of the 33 possible components of orange,

M. Morvai; I. Molnr-Perl

1992-01-01

359

Novel S-adenosyl- l-methionine:salicylic acid carboxyl methyltransferase, an enzyme responsible for biosynthesis of methyl salicylate and methyl benzoate, is not involved in floral scent production in snapdragon flowers  

Microsoft Academic Search

Using a functional genomic approach we have isolated and characterized a cDNA that encodes a salicylic acid carboxyl methyltransferase (SAMT) from Antirrhinum majus. The sequence of the protein encoded by SAMT has higher amino acid identity to Clarkia breweri SAMT than to snapdragon benzoic acid carboxyl methyltransferase (BAMT) (55 and 40% amino acid identity, respectively). Escherichia coli-expressed SAMT protein catalyzes

Florence Negre; Natalia Kolosova; Joseph Knoll; Christine M Kish; Natalia Dudareva

2002-01-01

360

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

PubMed

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. PMID:24309180

Mohammadi, Khosro; Niad, Mahmood; Jafari, Tahereh

2014-03-25

361

Succinic Acid in Wines.  

National Technical Information Service (NTIS)

Following a brief discussion of methods which are currently employed to determine the succinic acid content of wines, as well as the shortcomings of those methods, procedures used for colorimetric evaluation of this particular acid are explained. The prin...

M. Castino

1969-01-01

362

Omega-3 fatty acids  

PubMed Central

OBJECTIVE To examine evidence for the role of omega-3 fatty acids in cardiovascular disease. QUALITY OF EVIDENCE PubMed was searched for articles on the role of omega-3 fatty acids in cardiovascular disease. Level I and II evidence indicates that omega-3 fatty acids are beneficial in improving cardiovascular outcomes. MAIN MESSAGE Dietary intake of omega-3 fatty acids has declined by 80% during the last 100 years, while intake of omega-6 fatty acids has greatly increased. Omega-3 fatty acids are cardioprotective mainly due to beneficial effects on arrhythmias, atherosclerosis, inflammation, and thrombosis. There is also evidence that they improve endothelial function, lower blood pressure, and significantly lower triglycerides. CONCLUSION There is good evidence in the literature that increasing intake of omega-3 fatty acids improves cardiac outcomes. Physicians need to integrate dietary recommendations for consumption of omega-3 fatty acids into their usual cardiovascular care.

Schwalfenberg, Gerry

2006-01-01

363

Acid Aerosols Issue Paper.  

National Technical Information Service (NTIS)

The report evaluates scientific information on direct health effects associated with exposure to acid aerosols. The present report is not intended as a complete and detailed review of all literature pertaining to acid aerosols. Rather, an attempt has been...

1988-01-01

364

Fatty acid analogs  

DOEpatents

In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

Elmaleh, David R. (Newton Center, MA); Livni, Eli (Brookline, MA)

1985-01-01

365

Polymerization of Itaconic Acid.  

National Technical Information Service (NTIS)

Itaconic acid has various uses in chain copolymerization reactions, because of its two carboxylic groups and relatively good reactivity with different comonomers. As an unsaturated dicarboxylic acid it also has applications in grafting reactions and polyc...

J. Ahlgren

1990-01-01

366

Sulfuric acid poisoning  

MedlinePLUS

Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This is for information only and not for ...

367

Folic Acid Quiz  

MedlinePLUS

... folic acid supplement d) eat a cup of broccoli 5. Spina bifida and anencephaly: Hint a) are ... acid every day. This question is tricky because broccoli is a natural source of food folate, however ...

368

Aminocaproic Acid Injection  

MedlinePLUS

Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

369

Hydrochloric acid poisoning  

MedlinePLUS

Hydrocholoric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This is for information only and not for ...

370

Facts about Folic Acid  

MedlinePLUS

... of the baby's brain and spine ( anencephaly and spina bifida ). How much folic acid a woman needs 400 ... audiocast about folic acid. Related Pages Healthy Pregnancy spina bifida Birth Defects CDCs National Center on Birth Defects ...

371

Uric acid - blood  

MedlinePLUS

Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in ... mackerel, dried beans and peas, and beer. Most uric acid dissolves in blood and travels to the kidneys. ...

372

Plasma amino acids  

MedlinePLUS

Plasma amino acids is a screening test done on infants that looks at the amounts of amino ... Rheumatoid arthritis High or low concentrations of individual plasma amino acids must be interpreted along with other ...

373

Chemically amplified kojic acid responses of tyrosinase-based biosensor, based on inhibitory effect to substrate recycling driven by tyrosinase and l-ascorbic acid  

Microsoft Academic Search

A tyrosinase-based chemically amplified biosensor, based on the substrate recycling of polyphenols driven by tyrosinase-catalyzed oxidation and chemical reduction by l-ascorbic acid (AsA), has been utilized for the highly sensitive detection of inhibitors of tyrosinase such as kojic acid, benzoic and SCN? ion. The amplified current response of immobilized tyrosinase-coupling oxygen electrode due to the recycling was suppressed by the

Yasushi Hasebe; Katsuhiro Oshima; Osamu Takise; Shunichi Uchiyama

1995-01-01

374

[Kinetic and mechanism of ozonation of terephthalic acid].  

PubMed

The effect of ozonation of terephthalic acid (TA) was evaluated, and the kinetic and mechanism of this process were also discussed. The rate constants of TA with ozone and OH radicals calculated by the relative method are (0.047 +/- 0.010) L x (mol x s)(-1) and 2.28 x 10(9) L x (mol x s)(-1), respectively. The above result was in accordance with the apparent reaction rate constant of ozonation of TA when the process was controlled by chemical reaction. Intermediates detected by high-performance liquid chromatography (HPLC) and ion chromatography (IC) included benzoic acid, tartaric acid, formic acid and oxalic acid, therefore the possible destruction pathway of ozonation of TA was proposed on the basis of above results. PMID:19662847

Zang, Xing-Jie; Tong, Shao-Ping; Ma, Chun-An

2009-06-15

375

Refining Lurgi tar acids  

SciTech Connect

There is disclosed a process for removing tar bases and neutral oils from the Lurgi tar acids by treating the tar acids with aqueous sodium bisulfate to change the tar bases to salts and to hydrolyze the neutral oils to hydrolysis products and distilling the tar acids to obtain refined tar acid as the distillate while the tar base salts and neutral oil hydrolysis products remain as residue.

Greco, N.P.

1984-04-17

376

Nucleic acid molecule  

US Patent & Trademark Office Database

The invention relates to an isolated nucleic acid molecule encoding a polypeptide capable of producing a triterpenoid hydrocarbon. The invention also relates to the encoded polypeptide, a vector comprising the nucleic acid molecule, a recombinant non-human organism comprising the nucleic acid molecule, and to methods of producing a triterpenoid hydrocarbon or an intermediate of biofuel using the nucleic acid molecule, polypeptide or recombinant organism.

2011-10-11

377

Linolenic acid deficiency  

Microsoft Academic Search

Linolenic acid deficiency has not been demonstrated clearly in warm blooded animals, yet circumstantial evidence suggests\\u000a that n?3 fatty acids may have functions in these animals. The fact that several species of fish definitely require dietary\\u000a n?3 fatty acids indicates that n?3 fatty acids have important and specific functions in these animals and suggests that such\\u000a functions may also be

J. Tinoco; R. Babcock; I. Hincenbergs; B. Medwadowski; P. Miljanich; M. A. Williams

1979-01-01

378

Plant fatty acid hydroxylases  

DOEpatents

This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

Somerville, Chris (Portola Valley, CA); Broun, Pierre (Burlingame, CA); van de Loo, Frank (Lexington, KY)

2001-01-01

379

Acid-fast stain  

MedlinePLUS

... The slide is then washed with an acid solution and a different stain is applied. Bacteria that hold onto the first dye are considered "acid-fast" because they resist the acid wash. This type of bacteria is associated with tuberculosis and other infections.

380

[alpha]-Oxocarboxylic Acids  

ERIC Educational Resources Information Center

Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH

Kerber, Robert C.; Fernando, Marian S.

2010-01-01

381

Energy and acid rain  

Microsoft Academic Search

Acid rain is one of the foremost environmental issues of the 1980s and will be of continuining importance to energy policy for several reasons. First, the pollutants that cause acid rain are projected to increase through the end of the century as the demand for energy grows and as coal replaces oil. Second, many of the effects of acid rain

R R Gould

1984-01-01

382

Acid (and Base) Rainbows  

NSDL National Science Digital Library

Learners use red cabbage juice and pH indicator paper to test the acidity and basicity of household materials. The activity links this concept of acids and bases to acid rain and other pollutants. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.

Kolenbrander, Amy; Yowell, Janet; Mach, Natalie; Zarske, Malinda S.; Carlson, Denise; Perez, Sharon

2004-01-01

383

Neutralizing Acids and Bases  

NSDL National Science Digital Library

Learners use their knowledge of color changes with red cabbage indicator to neutralize an acidic solution with a base and then neutralize a basic solution with an acid. Use this as a follow-up activity to the related activity, "Color Changes with Acids and Bases."

Kessler, James H.; Galvan, Patricia M.

2007-01-01

384

The Acid Rain Reader.  

ERIC Educational Resources Information Center

A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)

Stubbs, Harriett S.; And Others

385

Crystallization of uric acid  

NASA Astrophysics Data System (ADS)

Crystals of uric acid have been grown in tetra methoxy silane and silica gel medium. Small winged, transparent, platy crystals of uric acid of about 0.5x0.5x0.1 mm were grown and were found to be hydrated uric acid.

Kalkura, S. Narayana; Vaidyan, V. K.; Kanakavel, M.; Ramasamy, P.

1993-09-01

386

The ground-state tunneling splitting of various carboxylic acid dimers  

NASA Astrophysics Data System (ADS)

Carboxylic acid dimers in gas phase reveal ground-state tunneling splittings due to a double proton transfer between the two subunits. In this study we apply a recently developed accurate semiclassical method to determine the ground-state tunneling splittings of eight different carboxylic acid derivative dimers (formic acid, benzoic acid, carbamic acid, fluoro formic acid, carbonic acid, glyoxylic acid, acrylic acid, and N,N-dimethyl carbamic acid) and their fully deuterated analogs. The calculated splittings range from 5.3e-4 to 0.13 cm-1 (for the deuterated species from 2.8e-7 to 3.3e-4 cm-1), thus indicating a strong substituent dependence of the splitting, which varies by more than two orders of magnitude. One reason for differences in the splittings could be addressed to different barriers heights, which vary from 6.3 to 8.8 kcal/mol, due to different mesomeric stabilization of the various transition states. The calculated splittings were compared to available experimental data and good agreement was found. A correlation could be found between the tunneling splitting and the energy barrier of the double proton transfer, as the splitting increases with increased strength of the hydrogen bonds. From this correlation an empirical formula was derived, which allows the prediction of the ground-state tunneling splitting of carboxylic acid dimers at a very low cost and the tunneling splittings for parahalogen substituted benzoic acid dimers is predicted.

Tautermann, Christofer S.; Voegele, Andreas F.; Liedl, Klaus R.

2004-01-01

387

The ground-state tunneling splitting of various carboxylic acid dimers.  

PubMed

Carboxylic acid dimers in gas phase reveal ground-state tunneling splittings due to a double proton transfer between the two subunits. In this study we apply a recently developed accurate semiclassical method to determine the ground-state tunneling splittings of eight different carboxylic acid derivative dimers (formic acid, benzoic acid, carbamic acid, fluoro formic acid, carbonic acid, glyoxylic acid, acrylic acid, and N,N-dimethyl carbamic acid) and their fully deuterated analogs. The calculated splittings range from 5.3e-4 to 0.13 cm(-1) (for the deuterated species from 2.8e-7 to 3.3e-4 cm(-1)), thus indicating a strong substituent dependence of the splitting, which varies by more than two orders of magnitude. One reason for differences in the splittings could be addressed to different barriers heights, which vary from 6.3 to 8.8 kcal/mol, due to different mesomeric stabilization of the various transition states. The calculated splittings were compared to available experimental data and good agreement was found. A correlation could be found between the tunneling splitting and the energy barrier of the double proton transfer, as the splitting increases with increased strength of the hydrogen bonds. From this correlation an empirical formula was derived, which allows the prediction of the ground-state tunneling splitting of carboxylic acid dimers at a very low cost and the tunneling splittings for parahalogen substituted benzoic acid dimers is predicted. PMID:15267897

Tautermann, Christofer S; Voegele, Andreas F; Liedl, Klaus R

2004-01-01

388

Nucleic acid detection compositions  

DOEpatents

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

Prudent, James R. (Madison, WI) [Madison, WI; Hall, Jeff G. (Madison, WI) [Madison, WI; Lyamichev, Victor I. (Madison, WI) [Madison, WI; Brow, Mary Ann (Madison, WI) [Madison, WI; Dahlberg, James L. (Madison, WI) [Madison, WI

2008-08-05

389

Cleavage of nucleic acids  

DOEpatents

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

2000-01-01

390

Cleavage of nucleic acids  

DOEpatents

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

Prudent, James R. (Madison, WI); Hall, Jeff G. (Waunakee, WI); Lyamichev, Victor I. (Madison, WI); Brow; Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

2010-11-09

391

Acid Rain: Students Site  

NSDL National Science Digital Library

This website introduces students to the concepts and issues surrounding acid rain. They will learn what acid rain is, how it forms, and what its effects are on humans, on the environment (lakes, rivers), and on infrastructure (buildings, monuments). There is also discussion of what is being done to reduce the presence of acid rain, and some suggestions for the students themselves to help reduce acid rain. A set of games, puzzles, and activities provides students with an opportunity to put their new knowledge of acid rain to use, and an animated slide show is provided to visually illustrate its causes and effects. A Spanish translation is available.

392

Cleavage of nucleic acids  

DOEpatents

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor L. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

2007-12-11

393

Amino acid analysis  

NASA Technical Reports Server (NTRS)

The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

Winitz, M.; Graff, J. (inventors)

1974-01-01

394

Identification of Phenolic Acid Composition of Alkali-extracted Plants and Soils  

Microsoft Academic Search

and plant growth (Rice, 1984), and are structural and functional components of soil organic matter (Haider Phenolic acids (PAs) released from plant residues have been impli- resulted in a highly reproducible and accurate method for the saponifi- coniferyl, and sinapyl alcohols (monolignols or phenyl- able PAs. The method quantified plant and soil PAs as ethanone (acetylbenzene), benzaldehyde, and benzoic- and

Dean A. Martens

2002-01-01

395

Demospongic Acids Revisited  

PubMed Central

The well-known fatty acids with a ?5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16C32) and from some terrestrial plants with short acyl chains (C18C19). Finally, the ?5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between ?5,9 fatty acids and other NMI FAs.

Kornprobst, Jean-Michel; Barnathan, Gilles

2010-01-01

396

[Biosynthesis of adipic acid].  

PubMed

Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production. PMID:24432653

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

2013-10-01

397

Process for the preparation of lactic acid and glyceric acid  

DOEpatents

Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

2008-12-02

398

NRPSs and amide ligases producing homopoly(amino acid)s and homooligo(amino acid)s.  

PubMed

Microorganisms are capable of producing a wide variety of biopolymers. Homopoly(amino acid)s and homooligo(amino acid)s, which are made up of only a single type of amino acid, are relatively rare; in fact, only two homopoly(amino acid)s have been known to occur in nature: poly(?-L-lysine) (?-PL) and poly(?-glutamic acid) (?-PGA). Bacterial enzymes that produce homooligo(amino acid)s, such as L-?-lysine-, L-valine-, L-leucine-, L-isoleucine-, L-methionine-, and L-glutamic acid-oligopeptides and poly(?-l-glutamic acid) (?-PGA) have recently been identified, as well as ?-PL synthetase and ?-PGA synthetase. This article reviews the current knowledge about these unique enzymes producing homopoly(amino acid)s and homooligo(amino acid)s. PMID:23817633

Hamano, Yoshimitsu; Arai, Toshinobu; Ashiuchi, Makoto; Kino, Kuniki

2013-08-01

399

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

PubMed

The degradation of 100mL 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(2) area, by applying a current of 100, 300 and 450 mA at 25C. Completed mineralization is always achieved due to the great concentration of hydroxyl radical (OH) generated at the BDD surface. The mineralization rate increases with increasing applied current, but decreases when drug concentration rises from 200 mg L(-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. PMID:23158689

Rabaaoui, Nejmeddine; Allagui, Mohamed Salah

2012-12-01

400

Efficacy of self-etching primers containing carboxylic acid monomers on the adhesion between composite resin and dentin.  

PubMed

A study was conducted to examine the efficacy of carboxylic acid monomers as self-etching primers by measuring the tensile bond strengths between composite resin and dentin. Several kinds of carboxylic acid monomers, such as o-(N-methacryloyl amino)benzoic acid (o-MABA), m-(N-methacryloyl amino)benzoic acid (m-MABA), p-(N-methacryloyl amino)benzoic acid (p-MABA), 4-methacryloxy phthalic acid (4-MPA), 2-(N-methacryloyl amino) terephthalic acid (2-MATPA), and 5-(N-methacryloyl) amino)isophthalic acid (5-MAIPA), were prepared. 4-methacryloxyethyl trimellitic anhydride (4-META) was also used as a component of the self-etching primer. The DMSO solutions of these monomers were used as self-etching primers. The tensile bond strengths between composite resin and dentin were measured after 24 h immersion in water at 37 degrees C. When DMSO was used as a self-etching primer, the bond strengths were below 5 MPa. Among the monocarboxylic acid monomers, m-MABA gave the highest mean bond strength at 60 s application, and 5MAIPA gave the highest mean bond strength at 30 s application among the dicarboxylic acid monomers, although the differences among the values were not always significant. The smear layer was partially dissolved by treatment with the self-etching primer. PMID:9663978

Hayakawa, T; Kikutake, K; Nemoto, K

1998-03-01

401

Inhibitory effect of organic acids on arcobacters in culture and their use for control of Arcobacter butzleri on chicken skin.  

PubMed

The inhibitory effects of 17 organic acids (C?-C?? fatty acids, sorbic, benzoic, phenylacetic, fumaric, succinic, lactic, malic and citric) on Arcobacter butzleri, Arcobacter cryaerophilus and Arcobacter skirrowii were investigated by determining their IC?? values, defined as the concentration of acid at which the target DNA sequence was expressed at 50% of the positive control level in cultures incubated at 30C for 24 h. DNA was analysed by real-time PCR. The Arcobacter strains tested were inhibited by all the organic acids, with the sensitivities in the order A. skirrowii > A. cryaerophilus > A. butzleri. Eight acids with IC?? values of <1 mg/mL against A. butzleri were tested for their effects on A. butzleri inoculated on chicken carcasses at a concentration of 5 log CFU/g of skin. Inoculated halved carcasses were immersed in solutions of the acids at 5 mg/mL for 1 min. Samples of skin were collected from carcass halves after storage at 4C for 0, 1, 2 or 3 days for enumeration of arcobacters on Muller-Hinton agar. All eight tested acids suppressed bacterial proliferation. The highest inhibitory activities were observed for benzoic, citric, malic and sorbic acids. Subsequent sensory analysis revealed benzoic acid to be the most suitable organic acid for chicken skin treatment. PMID:21084127

Sk?ivanov, Eva; Molatov, Zuzana; Mat?nov, Michaela; Houf, Kurt; Marounek, Milan

2011-01-01

402

Aerobic biodegradation of 2,2'-dithiodibenzoic acid produced from dibenzothiophene metabolites  

SciTech Connect

Dibenzothiophene is a sulfur heterocycle found in crude oils and coal. The biodegradation of dibenzothiophene through the Kodama pathway by Pseudomonas sp. strain BT1d leads to the formation of three disulfides: 2-oxo-2-(2-thiophenyl)ethanoic acid disulfide, 2-oxo-2-(2-thiophenyl)ethanoic acid-2-benzoic acid disulfide, and 2,2'-dithiodibenzoic acid. When provided as the carbon and sulfur source in liquid medium, 2,2'-dithiodibenzoic acid was degraded by soil enrichment cultures. Two bacterial isolates, designated strains RM1 and RM6, degraded 2,2'-dithiodibenzoic acid when combined in the medium. Isolate RM6 was found to have an absolute requirement for vitamin B{sub 12}, and it degraded 2,2'-dithiodibenzoic acid in pure culture when the medium was supplemented with this vitamin. Isolate RM6 also degraded 2,2'-dithiodibenzoic acid in medium containing sterilized supernatants from cultures of isolate RM1 grown on glucose or benzoate. Isolate RM6 was identified as a member of the genus Variovorax using the Biolog system and 16S rRNA gene analysis. Although the mechanism of disulfide metabolism could not be determined, benzoic acid was detected as a transient metabolite of 2,2'-dithiodibenzoic acid biodegradation by Variovorax sp. strain RM6. In pure culture, this isolate mineralized 2,2'-dithiodibenzoic acid, releasing 59% of the carbon as carbon dioxide and 88% of the sulfur as sulfate.

Young, R.F.; Cheng, S.M.; Fedorak, P.M. [University of Alberta, Edmonton, AB (Canada). Dept. of Biological Science

2006-01-15

403

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

PubMed

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. PMID:8302955

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

1993-12-01

404

Ozonation kinetics of phenolic acids present in wastewaters from olive oil mills  

Microsoft Academic Search

A kinetic study of the degradation by ozone of eight phenolic acids present in wastewaters from olive oil mills has been performed by using a competition kinetic method. The selected phenolic acids are: caffeic, p-coumaric, syringic, vanillic, 3,4,5-trimethoxybenzoic, veratric, p-hydroxy-benzoic, and protocatechuic. The influence of the operating variables (temperature, pH, and ozone partial pressure in the gas stream) is established,

F. Javier Bentez; J. Beltran-Heredia; Juan L. Acero; Maria L. Pinilla

1997-01-01

405

Substituent effects in hydrogen bonding: DFT and QTAIM studies on acids and carboxylates complexes with formamide.  

PubMed

Four series of hydrogen bonded complexes of formamide and substituted benzoic acids and benzoates were studied in the light of substituent effect on intermolecular interactions. The analysis based on energy of interaction, geometry, QTAIM-derived properties of hydrogen bond critical point and energy of hydrogen bonds were made and discussed. The opposite effect of the substituent on hydrogen bond donor and acceptor in acid series was found and analyzed. The isodesmic reactions were used to further study the interaction preferences. PMID:25024009

O?mia?owski, Borys

2014-08-01

406

Glycolic Acid 15% Plus Salicylic Acid 2%  

PubMed Central

Background: Facial flat warts are a contagious viral disease that can cause disturbing cosmetic problems. Topical glycolic acid has been reported to be effective in dermatological treatment depending on the exfoliant capacity, but has not often been reported to be effective in the treatment of facial flat warts. Objective: The aim of this paper was to evaluate the efficacy and safety of glycolic acid 15% topical gel plus salicylic acid 2% in the treatment of recalcitrant facial flat warts. Methods: A total of 20 consecutive patients 7 to 16 years of age with recalcitrant facial flat warts were enrolled in this study. Patients having warts by the eye and lip regions were excluded from the study. A fine layer of face gel was applied to the treatment area once daily. Most of the participants had tried different treatments with no success. Assessments for the response and the occurrence of side effects were performed every two weeks at Weeks 2, 4, 6, and 8. Results: All the patients were clinically cured within eight weeks. Seven patients cleared in four weeks, and 13 patients cleared in eight weeks. No noticeable adverse events were related to the skin. Conclusion: Topical gel of glycolic acid 15% plus salicylic acid 2% is safe and effective when applied to facial flat warts once daily until clearance and may be considered as first-line treatment.

Sanchez-Blanco, Elena

2011-01-01

407

21 CFR 172.860 - Fatty acids.  

Code of Federal Regulations, 2010 CFR

...and oils derived from edible sources: Capric acid, caprylic acid, lauric acid, myristic acid, oleic acid, palmitic acid, and stearic acid. (b) The food additive meets the following specifications: (1) Unsaponifiable matter does...

2009-04-01

408

21 CFR 172.860 - Fatty acids.  

Code of Federal Regulations, 2010 CFR

...and oils derived from edible sources: Capric acid, caprylic acid, lauric acid, myristic acid, oleic acid, palmitic acid, and stearic acid. (b) The food additive meets the following specifications: (1) Unsaponifiable matter does...

2010-01-01

409

21 CFR 172.860 - Fatty acids.  

Code of Federal Regulations, 2013 CFR

...and oils derived from edible sources: Capric acid, caprylic acid, lauric acid, myristic acid, oleic acid, palmitic acid, and stearic acid. (b) The food additive meets the following specifications: (1) Unsaponifiable matter does...

2013-04-01

410

Kinetic acidity of cubane  

SciTech Connect

The authors have determined the kinetic acidity of cubane by the application of a {sup 3}H NMR spectroscopic approach. An earlier measurement of the acidity of cubane has been subject to some controversy. Kinetic acidities are a useful measure of the acidity of weak carbon acids and are obtained by measuring rates of base-catalyzed proton-exchange reactions. It has been found that one-bond {sup 13}C-{sup 1}H NMR coupling constants ({sup 1}J{sub CH}) correlate closely with kinetic acidities for cyclic aliphatic hydrocarbons. This correlation holds even for strongly strained systems such as cyclopropane. Cubane, a strained polycycloalkane, would be anticipated to also fit this correlation.

Dixon, R.E.; Streitwieser, A. (Univ. of California, Berkeley (USA)); Williams, P.G. (Lawrence Berkeley Lab., CA (USA)); Eaton, P.E. (Univ. of Chicago, IL (USA))

1991-01-02

411

Acid Rain Learning Activities  

NSDL National Science Digital Library

These suggestions for activities allow students to learn about acid deposition in new and interactive ways, both in and out of the classroom. The suggestions are for individuals and small groups, the class as a whole, or for field trips. Students may contact local experts about acid rain issues, investigate the energy sources used to generate electricity by their local power companies, collect cartoons about acid rain and air pollution, or play the roles of scientists or interested parties involved in investigations of acid rain issues. Field trip ideas include visiting a local museum or science center to see exhibits or resources on acid rain, and visiting a local cemetary to examine the effects of acid rain on the headstones.

412

of natural amino acids  

Microsoft Academic Search

A new method for the synthesis of protected N a -(-Y-alkyl) amino acids (Y is a thio, amino or carboxy group) and related compounds by reductive alkylation of natural amino acids is reported. These new amino acids serve as building units for the synthesis of backbone-cyclic peptides. They are orthogonally protected at the -amino position by butoxycarbonyl (Boc) or 9-fluorenylmethoxycarbonyl

Gal Bitan; Dan Muller; Ron Kasher; Evgenia V. Gluhov; Chaim Gilon

1997-01-01

413

Acid-Base Solutions  

NSDL National Science Digital Library

How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?

Simulations, Phet I.; Lancaster, Kelly; Malley, Chris; Loeblein, Patricia; Parson, Robert; Perkins, Kathy

2010-09-01

414

Characterization of acid tars  

Microsoft Academic Search

Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography\\/mass spectrometry (GC\\/MS), inductively coupled plasma\\/optical emission spectrometry (ICP\\/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy\\/energy dispersive X-ray (SEM\\/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48h batch tests with distilled water at a liquid-to-solid ratio

Sunday A. Leonard; Julia A. Stegemann; Amitava Roy

2010-01-01

415

THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE  

EPA Science Inventory

This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

416

USGS Tracks Acid Rain  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

1995-01-01

417

Automobiles and acid rain  

SciTech Connect

In his editorial Acid rain Philip H. Abelson writes that everyone who drives an automobile is a contributor to acid rain. Examination of emissions data indicates that controlling automobile emissions will contribute little to solving acid precipitation problems. Of the strong acid anions associated with precipitation acidity, sulfate accounts for about 60% and nitrate for about 40%, on an equivalence basis. The contribution to national SO/sub 2/ emissions by all forms of transportation is about 3%. The corresponding value for national NO/sub x/ emissions is about 44%. If ground-level emissions from highway vehicles contribute to long-range transport of atmospheric pollutants and to precipitation acidity on an equal basis with other sources, for example, power plant smokestacks, then the respective contributions to precipitation acidity can be approximated. The atmospheric chemistry of NO/sub x/ and its interaction with SO/sub 2/ is poorly known. However, it is likely that automobiles account for less than 14% of total equivalents of strong acid anions in either wet or dry deposition in the eastern US. The implication of these data for regulatory policies aimed at controlling acid precipitation by reducing SO/sub 2/ and NO/sub x/ emissions is obvious.

Hendrey, G.R.

1985-01-01

418

Hydrogen-bond induced side-chain liquid crystalline polymers based on nicotinic acid derivatives  

Microsoft Academic Search

Supramolecular side-chain liquid crystalline poly(acrylate)s have been prepared by self-assembly of H-bond donor and acceptor complexes through intermolecular complementary hydrogen bond formation. Poly[4-(m-acryloyloxyalkyloxy)benzoic acid]s [m=6 (P1) and 8 (P2)] were employed as polymer components. Liquid crystalline nicotinic acid derivatives (C1, C2, C3, and C4) were used as complementary H-bond donor\\/acceptor counterparts. The liquid crystalline properties of the nicotinic acid derivatives,

C. Saravanan; V. Ambili; P. Kannan

2010-01-01

419

Molecular Structure of Fumaric acid  

NSDL National Science Digital Library

Fumaric acid is odorless and colorless or white crystalline powder with a fruit acid taste. Fumaric acid is used as a substitute of tartaric acid in beverages and baking powders and as a replacement for citric acid in fruits drinks. It is also used as antioxidant to prevent rancidity in butter, cheese, powdered milk, and other foodstuff. In addition, fumaric acid is a chemical intermediate in the manufacture of pharmaceuticals, synthetic resins and plastics. Fumaric acid can be prepared by catalytic oxidation of benzene or by bacterial action on glucose and it is involved in the production of energy from food. Fumaric acid (known as trans-butanedioic acid) is the trans isomer of maleic acid (also called cis-butanedioic acid). Fumaric acid is more stable than maleic acid and can be prepared by heating maleic acid.

2004-11-05

420

Measurements and modeling of the phase behavior of ternary systems of interest for the GAS process: I. The system carbon dioxide+1-propanol+salicylic acid  

Microsoft Academic Search

As a representative model system for the gas-anti-solvent (GAS) process, the phase behavior of the ternary system carbon dioxide+1-propanol+salicylic acid has been studied experimentally. For this purpose, carbon dioxide has been chosen as the anti-solvent gas, 1-propanol as the organic solvent, and salicylic acid (2-hydroxy benzoic acid) as the model drug. In each experiment, a solution of salicylic acid in

A. Shariati; C. J. Peters

2002-01-01

421

Structure of Acid phosphatases.  

PubMed

Acid phosphatases are enzymes that have been studied extensively due to the fact that their dysregulation is associated with pathophysiological conditions. This characteristic has been exploited for the development of diagnostic and therapeutic methods. As an example, prostatic acid phosphatase was the first marker for metastatic prostate cancer diagnosis and the dysregulation of tartrate resistant acid phosphatase is associated with abnormal bone resorption linked to osteoporosis. The pioneering crystallization studies on prostatic acid phosphatase and mammalian tartrate-resistant acid phosphatase conformed significant milestones towards the elucidation of the mechanisms followed by these enzymes (Schneider et al., EMBO J 12:2609-2615, 1993). Acid phosphatases are also found in nonmammalian species such as bacteria, fungi, parasites, and plants, and most of them share structural similarities with mammalian acid phosphatase enzymes. Acid phosphatase (EC 3.1.3.2) enzymes catalyze the hydrolysis of phosphate monoesters following the general equation. Phosphate monoester + H2O -->/<-- alcohol + phosphate. The general classification "acid phosphatase" relies only on the optimum acidic pH for the enzymatic activity in assay conditions using non-physiological substrates. These enzymes accept a wide range of substrates in vitro, ranging from small organic molecules to phosphoproteins, constituting a heterogeneous group of enzymes from the structural point of view. These structural differences account for the divergence in cofactor dependences and behavior against substrates, inhibitors, and activators. In this group only the tartrate-resistant acid phosphatase is a metallo-enzyme whereas the other members do not require metal-ion binding for their catalytic activity. In addition, tartrate-resistant acid phosphatase and erythrocytic acid phosphatase are not inhibited by L-(+)-tartrate ion while the prostatic acid phosphatase is tartrate-sensitive. This is an important difference that can be exploited in in vitro assays to differentiate between different kinds of phosphatase activity. The search for more sensitive and specific methods of detection in clinical laboratory applications led to the development of radioimmunoassays (RIA) for determination of prostatic acid phosphatase in serum. These methods permit the direct quantification of the enzyme regardless of its activity status. Therefore, an independent structural classification exists that helps to group these enzymes according to their structural features and mechanisms. Based on this we can distinguish the histidine acid phosphatases (Van Etten, Ann N Y Acad Sci 390:27-51, 1982), the low molecular weight protein tyrosine acid phosphatases and the metal-ion dependent phosphatases. A note of caution is worthwhile mentioning here. The nomenclature of acid phosphatases has not been particularly easy for those new to the subject. Unfortunately, the acronym PAP is very common in the literature about purple acid phosphatases and prostatic acid phosphatase. In addition, LPAP is the acronym chosen to refer to the lysophosphatidic acid phosphatase which is a different enzyme. It is important to bear in mind this distinction while reviewing the literature to avoid confusion. PMID:23860654

Araujo, Csar L; Vihko, Pirkko T

2013-01-01

422

Exocarpic acid inhibits mycolic acid biosynthesis in Mycobacterium tuberculosis.  

PubMed

Exocarpic acid (13 E-octadecene-9,11-diynoic acid) from Exocarpos latifolius R.Br. (Santalaceae) was previously shown to have specific antimycobacterial activity. Microarray data suggested inhibition of fatty acid metabolism as a potential mode of action. Experiments designed to elucidate the mechanism of action showed that exocarpic acid was effective at inhibition of mycolic acid biosynthesis and did not act by dissipating the proton gradient in treated M. tuberculosis. Amide derivatives of exocarpic acid displayed similar properties to exocarpic acid, while other polyacetylenic fatty acids varied in their effects on mycolic acid biosynthesis. PMID:20506078

Koch, Michael; Bugni, Tim S; Sondossi, Mohammad; Ireland, Chris M; Barrows, Louis R

2010-10-01

423

What Causes Acid Rain?  

NSDL National Science Digital Library

The phenomenon is the formation of acid rain. The resource explains the chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air, mix and react with water and other chemicals to form more acidic pollutants that dissolve very easily in water and can be carried long distances where they become part of rain, sleet, snow, and fog.

424

Iodinated humic acids  

NASA Astrophysics Data System (ADS)

Humic acids are iodinated by elemental iodine and, if the iodine is present as iodide, by peroxidase-mediated reactions. It is demonstrated that iodination of humic acids leads to a product with a uniform distribution of iodine. It could not be unambiguously verified whether the enzymatically mediated iodination is a direct reaction between a peroxidase-iodine complex and the humic acid molecule or a two-step reaction in which the enzyme creates elemental iodine, which consecutively reacts with the humic acid. Based on a simple model of a reaction between sites in the humic acids available for iodination and the electrophilic iodinating species, it was concluded that the reaction should be described as an equilibrium with a logarithmic equilibrium constant of approximately 4. The number of sites available for iodination was, in the humic acids studied, determined to be approximately 410-4 per gram humic acid. The different parameters influencing the enzymatically controlled iodination of humic acids are discussed.

Christiansen, Jesper V.; Carlsen, Lars

425

Characterization of acid tars.  

PubMed

Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain. PMID:19857924

Leonard, Sunday A; Stegemann, Julia A; Roy, Amitava

2010-03-15

426

EFFECTS OF ACID PRECIPITATION  

EPA Science Inventory

Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...

427

Acid rain options  

SciTech Connect

A number of contributions made to a series of seminars on acid rain options held by the Air Pollution Control Association are presented. They include statements on US and Canadian policy and legislation, and views from coal producers, electric utilities and motor vehicle manufacturers on measures to counteract or prevent the effects of acid rain.

Perhac, R.M.

1985-03-01

428

Analysis of Organic Acids.  

ERIC Educational Resources Information Center

Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

Griswold, John R.; Rauner, Richard A.

1990-01-01

429

Altered retmoic acid receptors  

Microsoft Academic Search

Structurally and functionally altered retinoic acid receptors have been associated with rare human neoplasms: acute promyelocytic leuke- mia and hepatoceilular carcinoma. Whereas the ret- inoic acid receptor 13 (RAR13) rearrangement in hepatocellular carcinoma is unique, in acute promyelocytic leukemia (APL), RARU fusion to the promyelocytic leukemia (PML) gene by the t(15;17) translocation is a general feature of the disease. APL

CNRS UPR; Service de Biochimie

430

Humus Acids of Soils.  

National Technical Information Service (NTIS)

Humus acids are known to occur widely in soils, peats, and natural waters. Soil fertility, migration and accumulation of minerals in natural landscapes, and mineral nutrition of plants are all associated with these acids. In recent times they have been us...

D. S. Orlov

1985-01-01

431

Lead-acid cell  

SciTech Connect

A lead-acid storage battery is described that has a lead negative electrode, a lead dioxide positive electrode and a sulfuric acid electrolyte having an organic catalyst dissolved therein which prevents dissolution of the electrodes into lead sulfate whereby in the course of discharge, the lead dioxide is reduced to lead oxide and the lead is oxidized.

Hradcovsky, R.J.; Kozak, O.R.

1980-12-09

432

Acid (and Base) Rainbows  

NSDL National Science Digital Library

Students are introduced to the differences between acids and bases and how to use indicators, such as pH paper and red cabbage juice, to distinguish between them. They learn why it is important for engineers to understand acids and bases.

Integrated Teaching And Learning Program

433

Acid in water  

NSDL National Science Digital Library

Plants and animals that live in water create some amount of acid in the water. The carbon dioxide that plants and animals release into the water makes the water acidic and unsafe for living organisms. This is why the water of captive aquatic animals and plants must be changed often.

Laszlo Ilyes (None;)

2007-05-16

434

Acids in Proteins  

NSDL National Science Digital Library

This lesson describes how amino acids build proteins in a person's body. Amino acids are the chemical building blocks for the structure of an organism. A link to a quiz is provided at the end of the lesson to check comprehension.

2012-06-19

435

Strong Acids (GCMP)  

NSDL National Science Digital Library

Strong Acids: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore the properties of common strong acids. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

436

Acids and Salts (GCMP)  

NSDL National Science Digital Library

Acids and Salts: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore a few properties of common acids and their salts. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

437

Lead-acid batteries  

Microsoft Academic Search

A method of producing a lead-acid battery capable of activation by the addition of electrolyte thereto, comprises the steps of: starting with a battery container accommodating at least one pack of battery plate grids having insulating separators interposed between adjacent grids, each of said grids carrying the lead-acid battery paste required to produce a positive or a negative battery plate

J. A. Bant; V. J. Raban

1980-01-01

438

ACID AEROSOLS ISSUE PAPER  

EPA Science Inventory

The report evaluates scientific information on direct health effects associated with exposure to acid aerosols. The present report is not intended as a complete and detailed review of all literature pertaining to acid aerosols. Rather, an attempt has been made to focus on the eva...

439

Acid Rain Revisited  

NSDL National Science Digital Library

The results of a long term study of the effects of acidic deposition in the Northeast were published in Bioscience this week, and they suggest that forests, lakes, and streams of the Northeastern US are not recovering from the toxic effects of acid rain despite significant cuts in the power plant emissions of sulfur dioxide and nitrogen oxide -- two major contributors to the problem. "Acid rain," more accurately called acidic deposition, causes toxic forms of aluminum to concentrate in soil and water, vital calcium and magnesium to be leached from trees, and surface waters to become inhospitable to aquatic biota. The study showed that, after 30 years of federally mandated air emission reductions, sulfur dioxide emissions have decreased while nitrogen oxide emissions have remained the same and that acidic deposition-related problems continue to plague New York and New England.

Sanders, Hilary C.

2001-01-01

440

Energy and acid rain  

SciTech Connect

Acid rain is one of the foremost environmental issues of the 1980s and will be of continuining importance to energy policy for several reasons. First, the pollutants that cause acid rain are projected to increase through the end of the century as the demand for energy grows and as coal replaces oil. Second, many of the effects of acid rain are cumulative, so that even at current levels of emissions the problem is expected to intensify and to spread geographically. Third, the transport of air pollutants across state and national boundaries has raised fundamental issues of equity that are likely to be disputed for some time. Finally, any serious program for reducing acid rain will exert a profound influence on the future development of energy supplies. This review summarizes the causes, effects, and transport of acid rain, and discusses possible strategies for mitigating the problem.

Gould, R.R.

1984-01-01

441

Airborne haloacetic acids.  

PubMed

Haloacetic acid (HAA) concentrations were measured in air samples from a semi-rural and a highly urbanized site in southern Ontario throughout 2000 to investigate their sources and gas-particle partitioning behavior. Denuders were efficient for collection of gaseous HAAs, and the particle phase was collected on a downstream quartz filter with negligible breakthrough. Total HAA concentrations (i.e., gas + particles) ranged between <0.025 and 19 ng m(-3) for individual HAAs at both sites. The dominant airborne HAA was monochloroacetic acid (MCA), followed in decreasing order by dichloroacetic acid (DCA), trifluoroacetic acid (TFA), and trichloroacetic acid (TCA). Difluoroacetic acid (DFA), monofluoroacetic acid (MFA), and chlorodifluoroacetic acid (CDFA) were also frequently detected at lower concentrations. Between sites, TFA, DFA, MFA, and TCA concentrations were significantly higher in Toronto, while CDFA concentrations were higher in Guelph. HAAs were primarily in the gas phase all year; however, during colder months, particle-phase HAA concentrations increased relative to the gas phase. Trichloroacetic acid had the highest particle fraction (phi) for all detected HAAs, with a mean phi of 0.51 and 0.56 for Guelph and Toronto, respectively, and both vapor pressure and acid strength appeared to influence gas-particle partitioning. Temporal trends at both sites were partially explained by temperature, short-wave radiation, and particle mass (PM10), leading to indications of the respective sources. A simple deposition model indicated that dry deposition of TFA and TCA should not be neglected in temperate mid-latitude environments and that precipitation concentrations can be successfully predicted by the Henry's law constant. PMID:12875391

Martin, Jonathan W; Mabury, Scott A; Wong, Charles S; Noventa, Francis; Solomon, Keith R; Alaee, Mehran; Muir, Derek C G

2003-07-01

442

Contribution of organic acids to the acidity of Finnish lakes.  

National Technical Information Service (NTIS)

This study provides a comprehensive assessment of the contribution of organic carbon and organic acids to the acid-base status of Finnish lakes, summarizing empirical organic acidity measurements (from 16 lakes) combined with the Finnish Lake Survey data ...

P. Kortelainen

1993-01-01

443

Acid recovery from waste sulfuric acid by diffusion dialysis  

Microsoft Academic Search

In the process of sulfuric acid production from pyrite, there is a lot of waste acid produced in fume washing with dilute\\u000a acid. Acid recovery from this sort of waste sulfuric acid by diffusion dialysis is studied in the paper. The mass transfer\\u000a dialysis coefficient of sulfuric acid of the membrane AFX is measured, the effect of the flowrate of

Guiqing Zhang; Qixiu Zhang; Kanggen Zhou

1999-01-01

444

Trans Fatty Acids  

NASA Astrophysics Data System (ADS)

Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

Doyle, Ellin

1997-09-01

445

Strongly Acidic Auxin Indole-3-Methanesulfonic Acid  

PubMed Central

A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles.

Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

1985-01-01

446

Understanding acid rain  

SciTech Connect

The complexities of the phenomenon of acid rain are described. Many factors, including meteorology, geology, chemistry, and biology, all play parts. Varying weather, varying soils, the presence of other pollutants and species differences all act to blur the connections between industrial emissions, acid rain, and environmental damage. Some experts believe that the greatest pH shock to lakes occurs during snow melt and runoff in the spring; others believe that much of the plant damage ascribed to acid rain is actually due to the effects of ozone. Much work needs to be done in the area of sampling. Historical data are lacking and sampling methods are not sufficiently accurate. (JMT)

Budiansky, S.

1981-06-01

447

Nucleic acid-based matrixes  

US Patent & Trademark Office Database

Various nucleic acid-based matrixes are provided, comprising nucleic acid monomers as building blocks, as well as nucleic acids encoding proteins, so as to produce novel biomaterials. Methods of utilizing such biomaterials include cell-free protein synthesis.

2013-07-16

448

Waste Acid Detoxification and Reclamation.  

National Technical Information Service (NTIS)

Economically feasible processes that reduce the volume, quantity, and toxicity of metal-bearing waste acids by reclaiming, reusing, and recycling spent acids and metal salts are being developed and demonstrated. The acids used in the demonstrations are ge...

T. M. Brouns T. L. Stewart

1988-01-01

449

WASTE ACID DETOXIFICATION AND RECLAMATION  

EPA Science Inventory

This Environmental Security Technology Certification Program (ESTCP) project demonstrated the Waste Acid Detoxification and Reclamation (WADR) systems ability to recover waste electropolish acid solutions generated during the manufacturing of gun-tubes, and reuse the clean acid. ...

450

Hydroxy-Conjugated Fatty Acids.  

National Technical Information Service (NTIS)

This invention relates to a method of producing hydroxy-conjugated octadecadienoic acid from linoleic acid contained in vegetable oils and soap stocks from alkali-refined vegetable oils. Linoleic acid soaps are dispersed in an aqueous medium containing di...

E. A. Emkeu

1973-01-01

451

The metabolic pathway of salicylic acid rather than of chlorogenic acid is involved in the stress-induced flowering of Pharbitis nil.  

PubMed

We examined the involvement of chlorogenic acid (CGA) and salicylic acid (SA) in the stress-induced flowering of Pharbitis nil (synonym Ipomoea nil). The incorporation efficiency of exogenously applied CGA and the deactivation rate of incorporated CGA were determined in cotyledons by high-performance liquid chromatography. The assay plants could not incorporate a sufficient amount of CGA via roots. The perfusion technique by which the assay solution was forced into the plant from the cut end of the hypocotyl improved the efficiency of CGA incorporation. However, no flower-inducing activity was detected, indicating that CGA was not involved in flowering. It was concluded that the close correlation between CGA content and flowering response is merely coincidence or a parallelism. Flowering under long-day conditions induced by low-temperature stress was completely inhibited by aminooxyacetic acid (AOA), an inhibitor of phenylalanine ammonialyase. The flower-inhibiting effect of AOA was nullified by co-applied t-cinnamic acid and by benzoic acid. This indicates that the metabolic pathway from t-cinnamic acid to SA via benzoic acid is involved in the stress-induced flowering. The results indicate that the metabolic pathway of SA is involved in the stress-induced flowering of P. nil not the metabolic pathway of CGA. PMID:12806773

Hatayama, Tomomi; Takeno, Kiyotoshi

2003-05-01

452

Nucleic Acid Cloning.  

National Technical Information Service (NTIS)

The present invention provides an improved system for linking nucleic acids to one another. In particular, the present invention provides techniques for producing DNA product molecules that may be easily and directly ligated to recipient molecules. The pr...

K. A. Jarrell V. W. Coljee W. Donahue S. Mikheeva

2001-01-01

453

(Acid rain workshop)  

SciTech Connect

The traveler presented a paper entitled Susceptibility of Asian Ecosystems to Soil-Mediated Acid Rain Damage'' at the Second Workshop on Acid Rain in Asia. The workshop was organized by the Asian Institute of Technology (Bangkok, Thailand), Argonne National Laboratory (Argonne, Illinois), and Resource Management Associates (Madison, Wisconsin) and was sponsored by the US Department of Energy, the United Nations Environment Program, the United Nations Economic and Social Commission for Asia and the Pacific, and the World Bank. Papers presented on the first day discussed how the experience gained with acid rain in North America and Europe might be applied to the Asian situation. Papers describing energy use projections, sulfur emissions, and effects of acid rain in several Asian countries were presented on the second day. The remaining time was allotted to discussion, planning, and writing plans for a future research program.

Turner, R.S.

1990-12-05

454

Aminolevulinic Acid Topical  

MedlinePLUS

... under the skin that result from exposure to sunlight and can develop into skin cancer) of the ... acid will make your skin very sensitive to sunlight (likely to get sunburn). Avoid exposure of treated ...

455

Acid-Base Tutorial  

NSDL National Science Digital Library

Website for anyone wanting to become more familiar with the physiology of acid-base balance in clinical medicine. Several pages are interactive. Numerical results are accompanied by text interpretations to facilitate recognition and understanding.

MD Alan W. Grogono (Tulane University School of Medicine Dept. of Anesthesiology)

2002-06-01

456

Stomach acid test  

MedlinePLUS

Gastric acid secretion test ... The test is done after a period of not eating so that fluid is all that remains in the ... the stomach through the esophagus (food pipe). To test the ability of the cells in the stomach ...

457

Amino Acids and Chirality  

NASA Technical Reports Server (NTRS)

Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

Cook, Jamie E.

2012-01-01

458

Infrared spectra and structure of molecular complexes of aromatic acids  

NASA Astrophysics Data System (ADS)

FTIR spectra of pharmacologically active molecules of benzoic acid and its derivatives have been measured in CCl4 solutions and in microcrystals. Features of the formation of intra-and intermolecular hydrogen bonds have been analyzed. Spectral attributes have been revealed that characterize the participation of a carboxyl group in different types of intermolecular interactions with the formation of cyclic, linear, and criss-cross dimers. Mechanisms of the intermolecular interactions are shown to be defined by the character of the substituents attached to the benzene ring in the para- and meta-positions relative to the carboxylic group.

Belkov, M. V.; Brinkevich, S. D.; Samovich, S. N.; Skornyakov, I. V.; Tolstorozhev, G. B.; Shadyro, O. I.

2012-01-01

459

Molecular Structure of Gallic acid  

NSDL National Science Digital Library

Gallic acid is found in its free state and combined with the tannin molecule, from which it can be extracted by the hydrolysis of tannic acid with sulfuric acid. Since one molecule of gallic acid has a carboxylic acid group and hydroxyl groups, it can react with another molecule of gallic acid to form an ester, digallic acid. When heated above 200 degrees C, gallic acid loses carbon dioxide to form pyrogallol (1,2,3-trihydroxybenzene, C6H3(OH)3), which is used in the production of azo dyes, photographic developers, and in laboratories for absorbing oxygen.

2003-05-08

460

Acid Rain Lesson Plan  

NSDL National Science Digital Library

Five articulated lessons focus on air quality using classroom and field data collection activities. Case study in Great Smoky Mountains has broader application. Background and data for lessons on: the pH scale, understanding acid vs. base, collecting data, mapping relationship of weather events to acid rain. Links to NPS data on air quality, current values, atlas and reports, packaged datasets on ozone, meteorological conditions and other parameters. Also available: teacher resources; educator workshops.

461

Inflammation, acid and ulcers.  

PubMed Central

Chronic active type B gastritis is invariably the result of Helicobacter pylori infection and is an important factor in duodenal ulcer disease. The actions of mediators produced (a protein factor, a lipid soluble "pore-forming factor" and urease) or induced (immune/inflammatory cell mediators) by this bacterium on the control of gastric acid secretion are currently being investigated. These studies are reviewed in light of our current knowledge of the physiological control of gastric acid secretion.

Muller, M. J.; Hunt, R. H.

1994-01-01

462

Domoic Acid Fact Sheet  

NSDL National Science Digital Library

This online fact sheet illustrates the transfer of domoic acid through the food web. Domoic acid is a nerve toxin produced by a naturally occurring Harmful Algal Bloom (HAB) usually (but not always) of the genus Pseudonitzchia. The sheet explains what to do if you find a sick or dead animal and includes contact information for injured/sick/entangled animal rescue networks in California.

Sanctuary, Channel I.

463

Effects of acid precipitation  

Microsoft Academic Search

Acid precipitation, including dry deposition, is recognized as coming from pollution-caused strong acid precursors that result from the burning of fossil fuels. Recent studies suggest that ecosystems susceptible to acid