Showing papers on "Benzoic acid published in 1987"

Photooxidation of organic impurities in water using thin films of titanium dioxide

Abstract: Results of the destruction of organic solutes in a simple, thin film TiO2 reactor are described. The reactor was illuminated with a 20-W blacklight UV fluorescent tube and the aqueous stream containing the organic solute flowed past the stationary photocatalyst. In the continuous recirculation mode, the destructive rate of each solute obeyed approximately first-order kinetics. The reaction rate constant decreased with increasing solute concentration. The times for 50% destruction of 500 cmT of 10 M solutions of each of the solutes salicylic acid, phenol, 2-chlorophenol, 4-chlorophenol, benzoic acid, 2-naphthol, naphthalene, and fluorescein were 7.1, 7.2, 8.2, 8.7, 6.9, 8.5, 4.3, and 6.4 min, respectively. It was found that the observed apparent first-order dependence and the change in rate constant with concentration could by explained in terms of the integrated form of the Langmuir adsorption isotherm. A marked dependence of the destruction rate on flow rate was observed and an expression developed which allows the calculation of the destruction curve with good precision at any solute concentration and flow rate. A corresponding curve was observed for the formation of carbon dioxide from salicylic acid solution. It was shown that hydroxylation of the aromatic ring to give salicylic acid is a minormore » reaction path in the destruction of benzoic acid. The maximum quantum yield for the destruction of salicyclic acid at 25C was found to be 0.022. The activation energy for the photooxidation of salicyclic acid was determined to be 11.0 +/- 0.8 kJ mol .« less

Chemical compositions and use as fuel additives

Abstract: Distillate fuel is treated with additives whose structure match the crystal planes of the wax which crystallizes from the fuel to produce crystals below 4000 nanometres in size, suitable additive include novel sulpho-carboxylic materials particularly their esters and amine derivatives such as the amine salts and/or amides of ortho-sulpho benzoic acid.

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

Abstract: 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 2-aminobenzoate (5 mM each) were oxidized to CO2 with the concurrent reduction of NO3-to NO2-. Only after complete NO3-consumption was NO2-reduced to N2. Cells contained a NADP-specific 2-oxoglutaate dehydrogenase, in contrast to a NAD-specific pyruvate dehydrogenase. During anaerobic metabolism of [carboxyl-14C]benzoic acid, 16% of the label of metabolized benzoic acid was incorporated into cell material; this excludes intermediary decarboxylation during anaerobic metabolism. Extracts catalysed the activation of benzoic acid and a variety of its derivatives to the respective aryl-coenzyme A thioesters, ATP being cleaved to AMP and PPi; two synthetase activites were present. Extracts from 2-aminobenzoate-grown cells catalyzed a NADH-dependent reduction of 2-aminobenzoyl-CoA (100 nmol·min-1·mg-1 cell protein) to an unidentified CoA thioester, with a stoichiometric release of NH3 and a stoichiometry of ≈ 3 mol NADH oxidized per mol 2-aminobenzyol-CoA reduced when tested under aerobic conditions. The 2-aminobenzoyl-CoA reductase activity was lacking in anaerobic benzoate-grown cells and in aerobic cells. This is taken as evidence that 2-aminobenzoyl-CoA reductase is a key enzyme in a novel reductive pathway of anaerobic 2-aminobenzoic acid metabolism.

Effects of weak acids and external pH on the intracellular pH of Zygosaccharomyces bailii, and its implications in weak-acid resistance.

Abstract: Weak acids and hydrogen ions in different concentration combinations affect the intracellular pH value (pHi) of Zygosaccharomyces bailii The lowest pHi value measured was not at the most extreme, but at intermediate conditions of inhibition Proton and organic-acid ejection, on a cell volume basis, is greater in cells grown under inhibitory conditions and is stimulated by weak acids, whilst in cells not grown under inhibitory conditions acid efflux is lower and is depressed by weak acids; this may be important in the maintenance of tolerable pHi values in the presence of weak acids The concentration of benzoic acid measured internally is identical to the value expected from its pK, external pH and pHi Addition of fructose to starved cells causes both a decreased pHi and a concomitant efflux of previously loaded benzoic acid, quantitatively in accord with the shift in equilibrium of the freely permeable undissociated acid There is no evidence that weak acids are actively extruded Protoplast volume also varies with hydrogen-ion and weak-acid concentration and this too may play a role in intracellular pH maintenace

New Methods for Preparing Cyclodextrin Inclusion Compounds. I. Heating in a Sealed Container

Abstract: A new method for preparing a solid inclusion compound was developed. A physical mixture of benzoic acid and α-or β-cyclodextrin (CD) or the ground mixture was sealed in a container after adsorbing a definite amount of water vapor, then heated to a temperature ranging from 43 to 142 °C. The results of powder X-ray diffraction and infrared spectroscopy showed that the crystalline inclusion compound was produced when the container was heated at over 70°C. The combining molar ratio of benzoic acid to α-CD in the inclusion compound prepared by this method was higher than that obtained by the coprecipitation method. Physical mixtures of benzoic acid and α-or β-CD were also sealed in a stainless steel vessel under nitrogen gas pressure, then heated to 127 °C. The pressurized samples had a higher combination ratio than the non-pressurized samples.

Mechanism of the desmutagenic effect of humic acid.

Abstract: The mechanism of an apparent desmutagenic effect of humic acid was investigated. Firstly, components of humic acid (resorcinol, vanillin, vanillic acid, ferulic acid, protochatechuic acid and benzoic acid) were tested and were not found to show a desmutagenic effect. By contrast, lignin did show a desmutagenic effect. The desmutagenic effect of humic acid was decreased by ozone treatment, and the degree of decrease corresponded with a decrease in KMnO4 consumption. Benzo[a]pyrene and humic acid were incubated at 37 degrees C for 1 h and extracted by ethyl acetate and the extract was investigated by gas chromatography (GC). The peak of the decomposition product did not appear, but the amount of benzo[a]pyrene was decreased. This suggests that the desmutagenic effect of humic acid was caused by adsorption of benzo[a]pyrene by humic acid rather than by decomposition of benzo[a]pyrene. Humic acid had the largest adsorption activity at its critical micelle concentration (CMC), while adsorbed benzo[a]pyrene could be released by ultrasonication. Fulvic acid and water-soluble humic substance showed a slight inhibitory effect on the mutagenicity of benzo[a]pyrene.

Comparison of electrochemical and ultraviolet detection methods in high-performance liquid chromatography for the determination of phenolic compounds commonly found in beers. Part 1. Optimisation of operating parameters

Abstract: The cyclic voltammetric behaviour of five benzoic acid derivatives, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid and syringic acid, four cinnamic acid derivatives, caffeic acid, p-coumaric acid, ferulic acid and sinapic acid, and two flavanols, (+)-catechin and (–)-epicatechin, commonly found in beers has been studied at a glassy carbon electrode. This study was used to optimise the conditions for the electrochemical detection of these compounds following high-performance liquid chromatographic (HPLC) separation. The HPLC method described is a modification of a previously described method and was optimised with respect to gradient profile, mobile phase composition and mobile phase flow-rate. A comparison was made between an ultraviolet detector and the electrochemical detector operated in series. In general, the electrochemical detector offered lower limits of detection for most of the phenolic compounds studied and, in addition, was found to offer better stability for the determination of concentrations in the 0.1–10.0 p.p.m. range.

The cyclometallation of benzoic acid to give rhodium, iridium, and osmium C,O-benzoates. X-Ray structure determination of the dibenzoate [(C5Me5)Rh(OOCPh)2(H2O)]

Abstract: The cyclometallated benzoate complexes [(C5Me5)[graphic omitted]H4)(Me2SO)][M = Rh (1a) or Ir (1b)] and [(p-MeC6H4CHMe2)O[graphic omitted]C6H4)(Me2SO)] were prepared by reaction of [(C5Me5)MMe2(Me2SO)] or [(p-MeC6H4CHMe2)OsMe(Cl)(Me2SO)] with benzoic acid or silver benzoate respectively. Methane was formed in these reactions. Complex (1b) was also prepared from [(C5Me5)IrCl2( Me2SO)] with silver benzoate. Complex (1a) reacted with water to give [{(C5Me5)Rh}2(µ-OH)3][OOCPh] and the dibenzoate hydrate [(C5Me5)Rh(OOCPh)2(H2O)](5a). Complex (5a) was also formed when (1a) was reacted with benzoic acid or when [(C5Me5)RhCl2(Me2SO)] reacted with two equivalents of silver benzoate. The structure of (5a) was determined by an X-ray study which showed two benzoates attached in a monodentate manner to the (C5Me5)Rh moiety; the rhodium also bore a co-ordinated water, which was also hydrogen-bonded to the two benzoate carbonyl oxygens. Both the rhodium and the iridium complexes (1a) and (1b), reacted with methyl iodide to give the cyclometallated methyl benzoate complexes [(C5Me5)[graphic omitted]H4}(I)]. They also underwent carbonylation to give phthalic anhydride and [(C5Me5)]Rh(CO)2 from (1a), and [(C5Me5)I[graphic omitted]H4)(CO)] from (1b). Mechanismsofthe various transformations are discussed.

Heterocyclic carboxylic acid amides and esters

Abstract: The dicarboxylic, heterocyclic and substituted benzoic acid alkylene bridged piperidyl amides and esters are serotonin M antagonists.

Heteroarotinoids. Synthesis, characterization, and biological activity in terms of an assessment of these systems to inhibit the induction of ornithine decarboxylase activity and to induce terminal differentiation of HL-60 cells

Abstract: The synthesis of certain heteroarotinoids has been achieved, namely the systems (2E,4E,6E)-3,7-dimethyl-7-(1,2,3,4-tetrahydro-4,4-dimethyl-6 -thiochromanyl)-2,4,6-heptatrienoic acid (1a), ethyl (2E,4E,6E)-3,7-dimethyl-7- (1,2,3,4-teterahydro-4,4-dimethyl-6-thiochromanyl)-2,4,6- heptatrienoate (1b), (2E,4E,6E)-3,7-dimethyl-7-(1,2,3,4-tetrahydro-4,4-dimethyl-6 -chromanyl)-2,4,6-heptatrienoic acid (1c), 2-phthalimidoethyl 3,7-dimethyl-7-(1,2,3,4-tetrahydro-4 4-dimethyl-6-thiochromanyl)-2,4,6-heptatrienoate (1d), methyl (E)-p-[2-(4,4- dimethyl-6-chromanyl)-1-propenyl]benzoate (2a), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzyl alcohol (2b), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzonitrile (2c), (E)-p-[2-(4,4-dimethyl-6-chromanyl)-1-propenyl]benzaldehyde (2d), methyl 4-[2-(2,3-dihydro-3,3-dimethyl-5-benzofuranyl)-1-propenyl] benzoate (3a), and (E)-p-[2-(2,3-dihydro-3,3-dimethyl-5-benzofuranyl)-1- propenyl]benzoic acid (3b). Characterization via elemental, IR, 1H NMR, and 13C NMR analyses was completed for these heterocycles. The biological activity of these heteroarotinoids was assayed by either the suppression of the 12-O-tetradecanoylphorbol 13-acetate (TPA) induced synthesis of ornithine decarboxylase (ODC) in mouse skin or the induction of differentiation of human (HL-60) promyelocytic cells. In the ODC assay, systems 1a-c exhibited strong activity (within 10% of or less than the control) whereas alcohols 2b and 3a showed good activity (within 50% of the control) as compared to either 13-cis-retinoic acid or trans-retinoic acid. Moderate activity was observed with 2a and 2b while 1d and 2c were essentially inactive. With the HL-60 assay, 1a and 1c were approximately 2- and 5-fold less active, respectively, than trans-retinoic acid. In contrast, 2a, 3a, and 3b induced differentiation of only a very small percentage of the cells. Acids 1a and 1c were the most active heteroarotinoids in the two biological assays. Consequently, the presence of the heteroatom does not eradicate the activity of the heteroarotinoids and thus they may have potential as chemotherapeutic agents.

Dissolution Characteristics of Benzoic Acid and Salicylic Acid Mixtures in Reactive Media

Abstract: The dissolution rates of mixtures of the two acids, benzoic acid and salicylic acid were determined in a phosphate buffered medium. Dissolution properties from compressed discs under sink conditions were essentially linear. Plots of dissolution rate versus compact composition deviated from the two component models for both non-interacting and interacting components. Dissolution rates, particularly for benzoic acid at intermediate weight fractions, were lower than predicted by the theory for two non-interacting components. These lower than expected rates were explained in terms of the physicochemical changes occurring in the microenvironment at the solid liquid interface.

Oscillations and complex mechanisms: O2 oxidation of benzaldehyde

Abstract: The oxidation of benzaldehyde catalyzed by cobalt and bromine is an oscillating reaction in which the concentrations of Co(III) and of dissolved oxygen vary periodically with time. A mechanistic model is proposed in which the reaction alternates between two stages. In stage I the dissolved oxygen concentration is appreciable and benzoyl radicals combine with oxygen, ultimately oxidizing Co(II) to Co(III). In stage II dissolved oxygen is depleted, and benzoyl radicals are oxidized by Co(III). The model gives satisfactory agreement with a number of qualitative and quantitative features. These include the composition of the steady states and the amplitude and period of oscillation for different concentrations of cobalt, bromide, and benzaldehyde. Specific measurements were also made of the kinetics of the reduction of cobalt(III) by mixtures of benzaldehyde and sodium bromide, the stability of a cobalt-bromide complex, and the consumption of /sup 18/O/sub 2/. This last study demonstrates the presence of two major pathways to benzoic acid which differ in the source of oxygen.

Pharmaceutically useful heterocyclic and carbocyclic acid esters and amides of alkylene bridged piperidines

Abstract: The dicarboxylic, heterocyclic and substituted benzoic acid alkylene bridged piperidyl amides and esters are serotonin M antagonists.

Electrolyte for driving electrolytic capacitor

Abstract: PROBLEM TO BE SOLVED: To improve the characteristics and reliability of an electrolytic capaci tor at a low cost by adding dimethylglyoxime to an electrolyte prepared by dissolving at least adipic acid or benzoic acid in a solvent prepared by mixing ethylene glycol with water. SOLUTION: An electrolyte for driving electrolytic capacitor is obtained by adding 0.01-3.0wt.% dimethylglyoxime to a solution prepared by dissolving at least one kind of organic carboxylic acid composed of adipic acid or benzoic acid or the salt of the acid in a solvent prepared by mixing ethylene glycol with 10-30wt.% water. Consequently, the occurrence of a gas can be suppressed, because the hydration between the water in the electrolyte and electrode foil at a high temperature is suppressed even when the adding amount of the water increases. Therefore, an electrolyte which has excellent electrical conductivity and is stable at a high temperature can be obtained.

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

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

Comparative Teratogenic Activity of Cancer Chemopreventive Retinoidal Benzoic Acid Congeners (Arotinoids)

Abstract: The benzoic acid derivatives of retinoic acid, often referred to as arotinoids, are synthetic retinoids that possess some of the properties of vitamin A. In general, these retinoids have more favorable therapeutic ratios, based on acute toxicity in adults, than all-trans-retinoic acid in cancer chemoprevention. In the present study, a single dose of (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8, 8-tetramethyl-2-naphthalenyl)-1-propen-1-yl]benzoic acid (Ro 13-7410; arotinoic acid), ethyl-(E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8- tetramethyl-2-naphthalenyl)-1-propen-1-yl]benzoate (Ro 13-6298; arotinoid ethyl ester), (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8, 8-tetramethyl-2-naphthalenyl)-1-propen-1-yl]phenylmethanol (Ro 13-8320; arotinoic methanol), or (E)-1,2,3,4-tetrahydro-1,1,4, 4-tetramethyl-6-[1-(4-methylphenyl)-1-propen-2-yl]naphthalene (Ro 13-9272; methyl arotinoid) was administered to pregnant Syrian golden hamsters during the early primitive streak stage of gestation. A significant increase in the numbers of litters containing one or more malformed offspring occurred at all doses of each retinoid studied. The types of malformations induced by oral arotinoid treatment were essentially identical to those found after maternal treatment with all-trans-retinoic acid or other teratogenic retinoids during the same gestational age. The results indicate that the alcohol congener was approximately 400 times more potent on a milligram per kilogram basis than all-trans-retinoic acid as a teratogen, and it was 70 times as embryolethal as all-trans-retinoic acid. The ethyl ester congener was 132 times, and the free acid 123 times, as embryolethal as all-trans-retinoic acid. On a molar basis, the arotinoic acid was at least 375 times as teratogenic as all-trans-retinoic acid and at least 140 times as teratogenic as etretinate in hamsters. Because the dose-response curves for arotinoids were significantly parallel to that for all-trans-retinoic acid, and because the spectrum of congenital defects induced by arotinoids was identical to that induced by all-trans-retinoic acid and other teratogenic retinoids, the mechanism of embryopathic action of these conformationally restricted retinoids was concluded to be similar to that of all-trans-retinoic acid.

Cationic surfactants based on quaternary ammonium compounds and use thereof in cleaning agents

Abstract: The invention relates to new cationic surfactants based on quaternary ammonium compounds which are characterized by the general formula ##STR1## wherein R 1 may be a linear or branched alkyl residue having from 1 to 22 carbon atoms; R 2 may be hydrogen or a linear or branched alkyl residue having from 1 to 21 carbon atoms, the total number of carbon atoms of the substituents R 1 and R 2 being in the range of from 8 to 22; R 3 and R 4 represent methyl, ethyl, 2-hydroxyethyl or 2-hydroxypropyl; R 5 represents an alkyl residue having from 4 to 6 carbon atoms or a phenalkyl residue having from 1 to 3 carbon atoms in the alkyl residue; and X - represents the anion of benzoic acid, of benzoic acid monosubstituted with CH 3 , NH 3 , NO 2 , COOH, OH or SO 3 H, of an aliphatic dicarboxylic acid having the general formula HOOC--(CH 2 ) n --COOH wherein n is a number from 2 to 8, of fumaric acid, of maleic acid or of sulfosuccinic acid; and the use of such cationic surfactants in industrial cleaning agents.

In vivo and in vitro renal metabolism and excretion of benzoic acid by a marine teleost, the southern flounder.

Abstract: In mammals, benzoic acid is primarily metabolized to its glycine conjugate, hippuric acid, which is readily excreted via the renal organic anion transport system. Teleost fish have not been shown to make glycine conjugates of carboxylic acids. Therefore, metabolism, excretion, and renal transport of benzoic acid were examined in the southern flounder, Paralichthys lethostigma. Excretion of injected [14C]benzoic acid was slow (10% of the administrated dose/day) and followed zero order kinetics. More than 95% of the excreted label was a single metabolite which was shown by hydrolysis and TLC to be benzoyltaurine. Isolated renal tubules and both hepatic and renal mitochondria produced benzoyltaurine in vitro. Excretion of benzoic acid and benzoyltaurine were not limited by plasma binding (less than 5% bound). To examine whether the slow excretion reflected renal transport, the transport of 100 microM benzoic acid, benzoyltaurine, and hippuric acid were determined in isolated renal tubules. All three compounds were accumulated via a probenecid- and cyanide-sensitive mechanism. Probenecid-sensitive uptake at 60 min of hippuric acid (436 nmol/mg) was greater than that of benzoyltaurine (164 nmol/mg) and both exceeded uptake of benzoic acid (63 nmol/mg). The same pattern was seen at 10 microM, except that tissue:medium ratios were even greater, indicating at least partial saturation of transport at 100 microM. Thus, the slow excretion of benzoic acid by these flounder was due to a combination of factors, including slow metabolism of benzoic acid to benzoyltaurine, saturation of the transport of benzoyltaurine, and low affinity of secretory transport for benzoic acid and benzoyltaurine, relative to hippuric acid, the mammalian metabolite.