Showing papers on "Benzoic acid published in 1980"

Methanogenic decomposition of ferulic acid, a model lignin derivative

Abstract: 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.

A refinement of the benzoic acid structure at room temperature

Abstract: C7H602, monoclinic, P21/e, a = 5.510(5), b = 5 . 1 5 7 ( 6 ) , c = 2 1 . 9 7 3 ( 8 ) ,&, f l = 9 7 . 4 1 ( 8 ) ° , Z = 4 , Dc= 1.31 Mg m -a. The cyclic hydrogenbonded dimers, arranged around the symmetry centres, are nearly planar, the torsion angle around the C C O 2 H bond being 1.5°. The benzene C atoms are coplanar within + 0 . 0 0 4 / k and the C C bond lengths average-1.388 (6) /k. The internal benzene angles deviate very slightly from the ideal value of 120 ° , ranging from 119.7 (4) to 120.5 (4) ° (mean 120.1°). The two C O bond lengths are nearly equal, their values being 1.263(3) and 1.275(4) /k. Correspondingly, the C C O angles are 118.8 (3) and 118.0 (4) °. The O . . . O bridge distance is 2.633 (3)/k. The C O bond lengths and the difference Fourier map indicate that there is a mixture of the two possible orientations of the dimer at the same crystal site. Introduetlon. After many attempts suitable single crystals were obtained from an alcohol-water mixture by slow evaporation. Cell parameters were determined by refinement of 21 reflexions on an automated single-crystal Siemens AED diffractometer. Intensity data were collected using a crystal of approximate dimensions 0.1 × 0.1 x 0.3 ram, mounted along b. Three-dimensional data were collected at 293 K using Mo Ka radiation by the 0-20 scan technique, within the limiting sphere of 0 = 27 °. A total of 469 independent reflexions having I > 2o(1) were collected and used in the calculations; Lorentz and polarization factors were applied but no correction was made for absorption. The structure was refined anisotropically starting from the parameters of the non-hydrogen atoms from the two-dimensional determination (Sim, Robertson & Goodwin, 1955). The benzene H atoms were placed in chemically reasonable positions ( C H , 1.00/k) and all occurred in regions of positive electron charge density on the difference Fourier map. On this map, an electron density peak of 0.2 e/~-3 appeared just in the middle of the O(1 ) -O(2 ' ) line (no other peak * To whom correspondence should be addressed. >0.1 e/~-3 was detected). This peak was assumed (see below) to be due to the overlap of two H atoms, with occupancy factors of one half ( O H , 0.90 ,&_, and / C O H , 119°). The final block-diagonal-matrix anisotropic refinement, including the contribution of the H atoms held constant (B = 6A2), gave a final R of 0 .038. t The final weighting scheme was W = I/(A + I Fol + BIFol2), where A = 3.5 and B = 0.012 were chosen so as to maintain w(IFol IFcl) 2 essentially constant over all ranges of IFol and sin 0/2. Atomic scattering factors were those of Moore (1963) and calculations were carried out with programs written by Albano, Domenicano & Vaciago (1966). The final atomic coordinates are given in Table 1 and the numbering scheme is shown in Fig. 1 together with bond lengths and angles. t Lists of structure factors and anisotropic thermal parameters have been deposited with the British Library Lending Division as Supplementary Publication No. SUP 35192 (4 pp.). Copies may be obtained through The Executive Secretary, International Union of Crystallography, 5 Abbey Square, Chester CH 1 2HU, England. Table 1. Fractional atomic coordinates (x 104, for H x l03) with estimated standard deviations in parentheses

Catabolism of aromatic acids in Trichosporon cutaneum.

Abstract: Trichosporon cutaneum readily metabolized protocatechuate, homoprotocatechuate, and gentisate, but lacked ring fission dioxygenases for these compounds. Benzoic, salicylic, 2,3-dihydroxybenzoic, and gentisic acids were converted into beta-ketoadipic acid before entry into the Krebs cycle. Benzoic acid gave rise successively to 4-hydroxybenzoic acid, protocatechuic acid, and hydroxyquinol (1,3,4-trihydroxybenzene), which underwent ring fission to maleylacetic acid. Salicylate and 2,3-dihydroxybenzoate were both initially metabolized to give catechol. 2,3-Dihydroxybenzoate was the substrate for a specific nonoxidative decarboxylase induced by salicylate, although 2,3-dihydroxybenzoate was not a catabolite of salicylate. Gentisate was metabolized to maleylacetic acid and was also readily attacked by salicylate hydroxylase at each stage of a partial purification procedure. Phenylacetic acid was degraded through 3-hydroxyphenylacetic, homogentisic, and maleylacetoacetic acids to acetoacetic and fumaric acids. All the reactions of these catabolic sequences were catalyzed by cell extracts, supplemented with reduced pyridine nucleotide coenzymes where necessary, except for the hydroxylations of benzoic and phenylacetic acids which were demonstrated with cell suspensions and isotopically labeled substrates.

Thin Layer Chromatographic Separation of Ortho, Meta, and Para Substituted Benzoic Acids and Phenols with Aqueous Solutions of α-Cyclodextrin

Abstract: The use of aqueous solutions of α-cyclodextrin as the mobile phase in thin layer chromatography (TLC) is described. A series of eighteen substituted benzoic acid compounds were chromatographed on polyamide thin layer sheets. The Rf values were dependent on the concentration of α-cyclodextrin in the mobile phase as well as the structure and size of the individual molecules. Possible advantages of this technique over those which use pure or mixed solvent systems as the mobile phase are discussed.

Inhibition of Aspergillus growth and aflatoxin release by derivatives of benzoic acid.

Abstract: A study was conducted to determine the effects of o-nitrobenzoate, p-aminobenzoate, benzocaine (ethyl aminobenzoate), ethyl benzoate, methyl benzoate, salicylic acid (o-hydroxybenzoate), trans-cinnamic acid (beta-phenylacrylic acid), trans-cinnamaldehyde (3-phenylpropenal), ferulic acid (p-hydroxy-3-methoxycinnamic acid), aspirin (o-acetoxy benzoic acid), and anthranilic acid (o-aminobenzoic acid) upon growth and aflatoxin release in Aspergillus flavus NRRL 3145 and A. parasiticus NRRL 3240. A chemically defined medium was supplemented with various concentrations of these compounds and inoculated with spores, and the developing cultures were incubated for 4, 6, and 8 days at 27 degree C in a mechanical shaker. At the beginning of day 8 of incubation, aflatoxins were extracted from cell-free filtrates, separated by thin-layer chromatography, and quantitated by ultraviolet spectrophotometry. The structure of these aromatic compounds appeared to be critically related to their effects on mycelial growth and aflatoxin release. At concentrations of 2.5 and 5.0 mg per 25 ml of medium, methyl benzoate and ethyl benzoate were the most effective in reducing both mycelial growth and aflatoxin release by A. flavus and A. parasiticus. Inhibition of mycelial growth and aflatoxin release by various concentrations of the above-named aromatic compounds may indicate the possibility of their use as fungicides.

Phenolic ethers in the organic polymer of the Murchison meteorite

Abstract: Seven phenolic acids and many nonphenolic organic acids, including large amounts of meta-hydroxy (3-hydroxy) benzoic acid and 3-hydroxy-1,5-benzene-dicarboxylic acid, were obtained from the organic polymer of the Murchison C2 chondrite upon oxidation with alkaline cupric oxide. The phenolic acids apparently were derived from phenolic ethers in the polymer, which in turn probably were formed from carbon monoxide and hydrogen by catalytic Fischer-Tropsch type reactions in the solar nebula. In contrast, terrestrial polymers such as lignin, humic acid, and coal yield mainly para-hydroxy (4-hydroxy) benzene derivatives by the same oxidation procedure.

Degradation of some phenoxy acid herbicides by mixed cultures of bacteria isolated from soil treated with 2-(2-methyl-4-chloro)phenoxypropionic acid.

Abstract: Mixed bacterial cultures capable of using 2-methyl-4-chIorophenoxyacetic acid (MCPA) and 2, 4-dichlorophenoxyacetic acid (2, 4-D) as the sole source of carbon and energy were isolated from field soil treated with the herbicide (±)2-(2-methyl-4-chloro)phenoxypropionic acid (mecoprop). An enrichment technique with two aromatic compounds as sources of carbon was used. Effects of temperature and substrate concentration were studied. The mixed cultures retained their ability to degrade MCPA although the bacteria were grown for 3 months (32 successive passages) with glucose as the sole source of carbon and energy. With benzoic acid as co-substrate, one of the cultures was also able to degrade mecoprop and (±)2-(2, 4-dichloro)phenoxypropionic acid (dichlorprop). This ability was not maintained, however, over more than 10 passages.

Heterogeneous photocatalytic decomposition of benzoic acid and adipic acid on platinized titanium dioxide powder. The photo-Kolbe decarboxylative route to the breakdown of the benzene ring and to the production of butane

Abstract: : The heterogeneous photocatalytic decomposition of adipic acid in deaerated aqueous solutions containing a suspension of platinized TiO2 (anatase) powder leads to the formation of CO2 and butane with lesser amounts of valeric acid and negligibly small quantities of oligomeric materials. A mechanism for this photo-Kolbe reaction, which yields different products than the electrochemical Kolbe reaction, is proposed. The photodecomposition of benzoic acid in oxygen-containing solution at platinized TiO2 was also investigated. The reaction product is predominantly CO2, with intermediate production of salicylic acid and phenol. A mechanism for the reaction based on photogeneration of hydroxyl radicals and adsorption of intermediates on the powder surface is proposed. (Author)

Colorimetric Detection and Determination of Carboxylic Acids with 2-Nitrophenylhydrazine Hydrochloride

Abstract: Aqueous or aqueous ethanolic samples of aliphatic and aromatic acids were coupled with 2-nitrophenylhydrazine hydrochloride to give acid hydrazides, which showed intense violet colors in an alkaline medium. Dicyclohexylcarbodiimide was used as a coupling agent, and a small amount of pyridine markedly enhanced the reaction. The brown blank solution was decolorized to a faint yellow by heating the alkaline solution at 60°. The reaction conditions were investigated in detail with acetic, stearic, benzoic and citric acids, and sensitive methods for the detection and determination of carboxylic acids were established. The limits of detection and the absorption maxima of the alkaline colors obtained with many carboxylic acids were determined. Most amino acids, together with hydroxybenzoic acids and aminobenzoic acids, were detected with reduced sensitivity by this method. Salicylic acid was shown by high-performance liquid chromatography and gas chromatography-mass fragmentography to form mainly its ehyl ester in the coupling reaction, whereas benzoic acid, which could be sensitively detected, formed only a small amount of the ester. p-Aminobenzoic acid also formed a large amount of its ethyl ester.

An Infrared Spectroscopic Flow Reactor for in Situ Studies of Heterogeneous Catalytic Reactions at High Temperature and the Reactions of CO 2 and Benzyl Benzoate on Alumina

Abstract: A simple infrared spectroscopic flow reactor has been fabricated for studying hetereogeneous catalytic reactions at elevated temperatures. Adsorption of CO2 on alumina and modified alumina catalysts shows the formation of several different surface carbonates. The hydrogen carbonate on alumina has a fast equilibrium with the gas phase. During the reduction of benzoic acid esters in this reactor, the formation of surface benzoate and carbonate has been observed. The desorption rate of the surface benzoate depends on the composition of the catalyst.

The metabolism of 3-phenoxybenzoic acid and its glucoside conjugate in rats

Abstract: 1. 3-Phenoxy[14C]benzoic acid administered orally to rats (0.76 to > 100mg/kg) is extensively metabolized and rapidly eliminated mostly via the urine.2. The major metabolic pathway involves 4′-hydroxylation followed by conjugation of the resulting phenol with sulphate. Only minor amounts of amino acid and glucuronic acid conjugation were observed.3. 3-Phenoxy[14C]benzoyl glucoside, derived from the metabolism of the acid by corn leaves, was also rapidly absorbed by rats and eliminated as a mixture of metabolites very similar to that derived from 3-phenoxybenzoic acid. It was concluded that the glucoside conjugate was rapidly hydrolysed to the free acid in vivo.

Polyester of para-hydroxy benzoic acid, 1,4-bis(para-carboxyphenoxy) benzene, aromatic diol and aromatic diacid capable of undergoing melt processing

Abstract: A novel polyester is provided which has been found to exhibit an optically anisotropic melt phase which enables it readily to undergo melt processing to form quality fibers, films, molded articles, etc. The polyester of the present invention contains recurring para-oxybenzoyl and para-phenylenedioxy-4,4'-dibenzoyl moieties in addition to moieties derived from at least one aromatic diol and at least one additional aromatic diacid in the proportions indicated. The hydrogen atoms present upon the aromatic rings derived from the aromatic diol and additional aromatic diacid optionally may be at least partially substituted (as described). The wholly aromatic polyester is capable of forming the desired anisotropic melt at a temperature below approximately 400° C., and in a preferred embodiment at a temperature below approximately 360° C.

Binding of Methyl Methacrylate to Bovine Serum Albumin

Abstract: Binding constants for methacrylates, acrylates, and miscellaneous vinyl monomers with bovine serum albumin were determined using 2-(4'-hydroxyphenylazo) benzoic acid (HABA). The influence of hydrophobic binding appeared to be more dominant in the bindings of methyl methacrylate.

Separation and Quantitation of Urinary Phthalates by HPLC

Abstract: A method was developed for the separation and quantitation of plasticizers and their metabolites from human urine using HPLC, Urine was diluted with an equal volume of water and extracted at pH 2.0 with diethyl ether, The extract was dried, the solvent vacuum stripped, and the residue dissolved in methanol for injection into the chromatograph. A C18 reverse phase column containing 10 μ particles was used for the analysis. Ionic suppression, 0.5% acetic acid in water, at pH 3.0 was used to resolve the acidic components. A step gradient of acetonitri1e:water (containing acetic acid) was used to elute the polar metabolites as well as the non-polar plasticizers. Mass spectrometry was used t o identify the compounds in the HPLC fractions. From the HPLC fractions of the urine extract collected, phthalic acid, MEHP, DEHP and normal urinary constituents (e.g., hippuric and benzoic acid derivatives) were identified

[Various methods for the determination of preservatives in food. I. Extraction and spectrophotometric determinations (author's transl)].

Abstract: In the Federal Republik of Germany formic acid, benzoic acid, propionic acid, sorbic acid and the esters of p-hydroxybenzoic acid were permitted as food-additives. They can be extracted together from acidified materials by means of perforation with ether. During distillation the preservatives are fixed by sodium hydroxide. The alkaline extract can then be used directly for various photometric (Part I) and chromatographic (Part II) determinations. All preservatives except propionic acid can be identified and determined by simple and specific color reaction. From the alkaline extract, benzoic acid, sorbic acid and the esters of p-hydroxybenzoic acid can be separated as the free acid by thin-layer chromatography on silica gel. Determination of the remission at 232 nm and 260 nm and of the reduction in fluorescence are employed for the photometric in situ evaluation of the thin-layer chromatograms.

Photoinduced oxidation of benzoic acid with aqueous hydrogen peroxide

Abstract: The photodecomposition of benzoic acid in aqueous hydrogen peroxide has been studied. When the ratio [H2O2]0/[PhCO2H]0 is low, the decomposition of benzoic acid and hydrogen peroxide stops during irradiation, while at a high [H2O2]0/[PhCO2H]0 ratio, benzoic acid is completely decomposed with cleavage of the aromatic ring. Hydroxybenzoic acid is a major product, and benzene and phenol are minor products during the initial stages of oxidation. Later lower aliphatic acids such as malonic acid appear. The probable mechanism for decomposition is discussed on the basis of product yields.