Showing papers on "Benzoic acid published in 1977"

Microbial metabolism of aromatic nitriles. Enzymology of C–N cleavage by Nocardia sp. (Rhodochrous group) N.C.I.B. 11216

Abstract: 1. An organism utilizing benzonitrile as sole carbon and nitrogen source was isolated by the enrichment-culture technique and identified as a Nocardia sp. of the rhodochrous group. 2. Respiration studies indicate that nitrile degradation proceeds through benzoic acid and catechol. 3. Cell-free extracts of benzonitrile-grown cells contain an enzyme that catalyses the conversion of benzonitrile directly into benzoic acid without intermediate formation of benzamide. 4. This nitrilase enzyme was purified by DEAE-cellulose chromatography and gel filtration on Sephadex G-100 in the presence and absence of substrate. The purity of the enzyme was confirmed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and isoelectric focusing on polyacrylamide gel. 5. The enzyme shows a time-dependent substrate-activation process in which the substrate catalyses the association of inactive subunits of mol.wt. 45000 to form the polymeric 12-unit active enzyme of mol.wt. 560000. The time required for complete association is highly dependent on the concentration of the enzyme, temperature and pH. 6. The associated enzyme has a pH optimum of 8.0 and Km with benzonitrile as substrate of 4mm. The activation energy of the reaction as deduced from the Arrhenius plot is 51.8kJ/mol. 7. Enzyme activity is inhibited by thiol-specific reagents and several metal ions. 8. Studies with different substrates indicate that the nitrilase is specific for nitrile groups directly attached to the benzene ring. Various substituents in the ring are compatible with activity, though ortho-substitution, except by fluorine, renders the nitrile invulnerable to attack. 9. The environmental implications of these findings and the possible significance of the enzyme in the regulation of metabolism are discussed.

On the Inhibition of Muscle Membrane Chloride Conductance by Aromatic Carboxylic Acids

Abstract: 25 aromatic carboxylic acids which are analogs of benzoic acid were tested in the rat diaphragm preparation for effects on chloride conductance (G(Cl)). Of the 25, 19 were shown to reduce membrane G(Cl) with little effect on other membrane parameters, although their apparent K(i) varied widely. This inhibition was reversible if exposure times were not prolonged. The most effective analog studied was anthracene-9-COOH (9-AC; K(i) = 1.1 x 10(-5) M). Active analogs produced concentration-dependent inhibition of a type consistent with interaction at a single site or group of sites having similar binding affinities, although a correlation could also be shown between lipophilicity and K(i). Structure-activity analysis indicated that hydrophobic ring substitution usually increased inhibitory activity while para polar substitutions reduced effectiveness. These compounds do not appear to inhibit G(Cl) by altering membrane surface charge and the inhibition produced is not voltage dependent. Qualitative characteristics of the I-V relationship for Cl(-) current are not altered. Conductance to all anions is not uniformly altered by these acids as would be expected from steric occlusion of a common channel. Concentrations of 9-AC reducing G(Cl) by more than 90 percent resulted in slight augmentation of G(I). The complete conductance sequence obtained at high levels of 9-AC was the reverse of that obtained under control conditions. Permeability sequences underwent progressive changes with increasing 9-AC concentration and ultimately inverted at high levels of the analog. Aromatic carboxylic acids appear to inhibit G(Cl) by binding to a specific intramembrane site and altering the selectivity sequence of the membrane anion channel.

Mechanism of Resistance of Saccharomyces bailii to Benzoic, Sorbic and Other Weak Acids Used as Food Preservatives

Abstract: Saccharomyces bailii grows in the presence of high concentrations of sorbic, benzoic and other short-chain monocarboxylic acids commonly used as preservatives. Starved cells concentrate these acids intracellularly, approximately as expected from the pH of the ceil and the pKa of the acid. On addition of glucose, the intracellular content of preservative is considerably reduced. The glucose effect is sensitive to metabolic inhibitors, and anaerobic respiration is stimulated by the preservatives. The ability to maintain a low intracellular concentration of any of the preservatives tested is induced by growth in the presence of sorbic or benzoic acid and less effectively by butyric or acetic acid. Both induced and uninduced cells are permeable to benzoic and butyric acids. Benzoate and sorbate are not metabolized at a rate significant with respect to the permeation rate. Resistance to these preservatives apparently results primarily from an inducible, energy requiring system which transports preservative from the cell.

Adsorption on hydrous oxides i. oxalate and benzoate on goethite

Abstract: Summary The adsorption of oxalic acid on synthetic goethite (α-FeOOH) was studied using adsorption isotherms. Infrared spectra were obtained for goethite-oxalate complexes at several points on the isotherms. On a goethite preparation with a phosphate sorption capacity of 200|μmolg−1 the amounts of oxalate strongly adsorbed varied from near zero at pH 8 to about l00μmolg−1 at pH 4 and below. At pH 3.4, the first l00μmolg−1 of oxalic acid added was strongly adsorbed as a binuclear complex (FeOOC–COOFe), replacing two singly-coordinated OH groups by ligand exchange. At higher concentrations a further 200 μrnol g−1 of oxalic acid formed a monodentate complex (FeOOC–COOH) so that more oxalate could be accommodated. Benzoic acid was weakly adsorbed on goethite with one benzoate oxygen replacing one singly-coordinated OH. The other oxygen of the COO group fitted into the goethite surface so that the benzene ring was at a high angle to the (100) face.

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

Abstract: 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 from the lake on benzoic acid in the presence of fulvic acid, fulvic acid of relatively small molecular size was formed from fulvic acid of relatively large molecular size, suggesting that microbial activity may play a role in the seasonal fluctuations in the molecular size distribution of fulvic acids in Tjeukemeer.

Identification of the luminescent species in low-density polyethylene

Abstract: The luminescence properties of two low-density polyethylene samples are examined, one prepared using oxygen and the other using a benzoyl-based initiator as catalysts. The fluorescence emission from both samples is assigned to the presence of an impurity, α,β-unsaturated carbonyl of the enone type. The phosphorescence emissions, on the other hand, are different. The phosphorescence emission from the sample prepared using oxygen as an initiator is assigned to the presence of a dienone impurity chromophore, whereas the emission from the sample prepared using a benzoyl-based initiator is assigned to benzoic acid residues.

Vibrational spectra and normal mode calculations of benzoic acid single crystals

Abstract: Raman and infrared spectroscopic studies of benzoic acid dimers and crystals have been made. Molecular and crystal normal modes have been calculated. An assignment of the observed spectra has been proposed and some specific modes discussed.

Synthese und Reaktionen 8‐gliedriger Heterocyclen aus 3‐Dimethylamino‐2,2‐dimethyl‐2H‐azirin und Saccharin bzw. Phthalimid

Abstract: Synthesis and Reactions of 8-membered Heterocycles from 3-Dimethylamino-2,2-dimethyl-2H-azirine and Saccharin or Phthalimide 3-Dimethylamino-2,2-dimethyl-2H-azirine (1) reacts at 0-20° with the NH-acidic compounds saccharin (2) and phthalimide (8) to give the 8-membered heterocycles 3-dimethylamino-4,4-dimethyl-5,6-dihydro-4 H-1,2,5-benzothiadiazocin-6-one-1,1-dioxide (3a) and 4-dimethylamino-3,3-dimethyl-1,2,3,6-tetrahydro-2,5-benzodiazocin-1,6-dione (9), respectively. The structure of 3a has been established by X-ray (chap. 2). A possible mechanism for the formation of 3a and 9 is given in Schemes 1 and 4. Reduction of 3a with sodium borohydride yields the 2-sulfamoylbenzamide derivative 4(Scheme 2); in methanolic solution 3a undergoes a rearrangement to give the methyl 2-sulfamoyl-benzoate 5. The mechanism for this reaction as suggested in Scheme 2 involves a ring contraction/ring opening sequence. Again a ring contraction is postulated to explain the formation of the 4H-imidazole derivative 7 during thermolysis of 3a at 180° (Scheme 3). The 2,5-benzodiazocine derivative 9 rearranges in alcoholic solvents to 2-(5′-dimethylamino-4′,4′-dimethyl-4′H-imidazol-2′-yl) benzoates (10, 11), in water to the corresponding benzoic acid 12, and in alcoholic solutions containing dimethylamine or pyrrolidine to the benzamides 13 and 14, respectively (Scheme 5). The reaction with amines takes place only in very polar solvents like alcohols or formamide, but not in acetonitrile. Possible mechanisms of these rearrangements are given in Scheme 5. Sodium borohydride reduction of 9 in 2-propanol yields 2-(5′-dimethylamino-4′,4′-dimethyl-4′H-imidazol-2′-yl)benzyl alcohol (15, Scheme 6) which is easily converted to the O-acetate 16. Hydrolysis of 15 with 3N HCl at 50° leads to an imidazolinone derivative 17a or 17b, whereas hydrolysis with 1N NaOH yields a mixture of phthalide (18) and 2-hydroxymethyl-benzoic acid (19, Scheme 6). The zwitterionic compound 20 (Scheme 7) results from the hydrolysis of the phthalimide-adduct 9 or the esters 11 and 12. Interestingly, compound 9 is thermally converted to the amide 13 and N-(1′-carbamoyl-1′-methylethyl)phthalimide (21, Scheme 7) whose structure has been established by an independent synthesis starting with phthalic anhydride and 2-amino-isobutyric acid. However, the reaction mechanism is not clear at this stage.

Partial characterization of the mode of action of benzoic acid on aflatoxin biosynthesis

Abstract: Aflatoxin production by a toxigenic strain of Aspergillus flavus was greatly reduced by benzoic acid and sodium benzoate in synthetic media. The reduction was accompanied by the appearance of a yel...

Apparatus for iso- or terephthalic acid production in and recovery from benzoic acid-water solvent system

Abstract: Continuous production of iso- or terephthalic acid in a stirred reaction zone by catalytic air oxidation of m- or p-xylene in the presence of a benzoic acid-water liquid solvent system at constant gauge pressure within the range of 7 to 21 kg/cm2 wherein oxidation temperature within the range of 175° to 235° C. is maintained substantially constant by the novel control thereof by only varying the flow rate of water condensate reflux to the oxidation zone. The invention further pertains to novel means for achieving such temperature control. Also, the present invention relates to a novel continuous recovery of the phthalic acid product from the fluid effluent of said continuous process by a process wherein crystalline phthalic acid product is separated from essentially water-free benzoic acid mother liquor; the crystalline product is successively washed with liquid benzoic acid and the corresponding xylene; the washed product is dried; and the water removed from said fluid effluent, the benzoic acid and xylene wash liquors, xylene recovered from product drying, and a major proportion of the benzoic acid mother liquor are charged to the oxidation process. The invention further relates to a novel combination of apparatus for the continuous conduct of said oxidation and recovery processes.

Synthetic plant growth regulators. The synthesis of C-o-Carboxyphenyl derivatives of some five-membered heterocycles

Abstract: Synthetic routes to o-carboxyphenyl derivatives of certain heterocyclic compounds, required for testing as plant growth regulators, were investigated. The preparation of 2-(5-phenyl-1,3,4-oxadiazol-2- yl)benzoic acid (3), 2-(5-phenyl-1,3,4-thiadiazol-2-yl)benzoic acid (4), 2-(5-phenyl-1H-1,2,4-triazol-3-yl)benzoic acid (5), 2-(3-phenyl- 1,2,4-oxadiazol-5-yl)benzoic acid (6), 2-(2-phenylthiazol-4-yl)benzoic acid (7), 2-(3-phenylisoxazol-5-yl)benzoic acid (8), 2-(5- phenylisoxazol-3-yl)benzoic acid (9) and chloro derivatives of (3), (4), (8) and (9) is described.

The metabolism of cyclohexanecarboxylic acid in the isolated perfused rat liver.

Abstract: 1. Cyclohexanecarboxylic acid in isolated perfused rat livers was eliminated from the perfusion system by a first-order process.2. After 6 h, 16% was excreted in bile as cyclohexylcarbonyl β-D-glucuronide. The remainder was present in the perfusate as unchanged cyclohexanecarboxylic acid (10%), hippuric acid (50%), hexahydrohippuric acid (2%), 3,4,5,6-tetra-hydrohippuric acid (2%), cyclohexylcarbonyl-β-D-glucuronide (2–4%) and benzoic acid (1–2%). Six per cent of the dose was associated with the red blood cells present in the perfusion medium.3. Unlike the whole animal, the isolated rat liver produced no detectable benzoyl glucuronide.4. The identity and kinetics of production of the metabolites are consistent with a metabolic pathway previously proposed for cyclohexanecarboxylic acid and shikimic acid.

Benzoyl cyanide in the defensive secretion of polydesmoid millipeds.

Abstract: A novel cyanogenetic compound, benzoyl cyanide, was isolated from the defensive secretion of 3 polydesmoid millipeds (Pseudopolydesmus serratus, Apheloria corrugata and A. trimaculata). The secretion of the 3 species also contains mandelonitrile and benzaldehyde, and that of P. serratus contains mandelonitrile benzoate, benzoic acid, isovaleric acid, myristic acid and stearic acid.

Anisole, acetophenone and benzoic acid methyl ester oriented in a nematic phase: Structure and internal motion

Abstract: 1H-, 1H{2D}-, 2D- and 2D{1H}-N.m.r.-spectra were used in an investigation of the partially oriented molecules anisole, acetophenone and benzoic acid methyl ester. The phenyl ring geometries were found to deviate slightly from the regular hexagon. For anisole and acetophenone the measured couplings indicate a structure with the substituent group in the plane of the ring and one of the methyl protons pointing away from it. It is not possible, however, to draw further conclusions on the depths and shapes of the potentials hindering the internal motions. For benzoic acid methyl ester the measurements indicate that the dominant conformer is the one with the OCH3 axis approximately parallel to the effective molecular C2-symmetry axis. Semiempirical MO calculations were found to provide reasonable molecular structures but no information on the potentials.

Curable water-borne epoxy resin coating compositions

Abstract: Hydrolytically-stable, water-soluble curable coating compositions are prepared by (1) condensing an epoxy resin with an amino-substituted aromatic carboxylic acid, preferably an amino-substituted benzoic acid, and then (2) essentially neutralizing the condensate with an amine, preferably a tertiary amine such as triethylamine and dimethylethanol amine or ammonia.

Internal Standards for Gas Chromatographic Analysis of Metabolic End Products from Anaerobic Bacteria

Abstract: 2-Methylpentanoic acid and benzoic acid are suggested for use as routine internal standards for gas chromatographic analysis of microbial end products.

Application of 2-trifluoromethanesulfonyloxypyridine in trifluoroacetic acid to acylation of aromatics

Abstract: New method for synthesis of aromatic ketones was investigated. 2-Trifluoromethanesulfonyloxypyridine (TSP) in trifluoroacetic acid was very useful in the condensation of carboxylic acids with some aromatic compounds to give aromatic ketones. The reaction of arenes with benzoic acid in the presence of TSP in trifluoroacetic acid gave benzoylarenes. By the same method, 2-acylfluorenes were obtained from carboxylic acids and fluorene.

Effects of Additives on the Asymmetric Hydrogenation of Methyl Acetoacetate Using Nickel-Palladium-Kieselguhr Catalyst Modified with Tartaric Acid

Abstract: Effects of additives on the asymmetric yield of methyl 3-hydroxybutyrate were examined in the hydrogenation of methyl acetoacetate using Ni-Pd-Kieselguhr catalyst modified with tartaric acid. Addition of unsaturated compounds such as dehydroacetic acid and diethyl maleate showed almost no effect on the asymmetric yield. Only when carboxylic acids having pKa values higher than that of tartaric acid such as formic acid, acetic acid, benzoic acid, and succinic acid were used as additives, great increase in asymmetric yield was observed.

Determination of saccharin in soft drinks by a spectrophotometric method

Abstract: Saccharin reacts quantitatively with phenothiazine (thiodiphenylamine) and copper(II) acetate dissolved in 50%V/V ethanol at 70 °C. The reaction product can be dissolved in an organic solvent and has a characteristic colour. The colour reaction is sensitive and the absorbance, at 510 nm, of the extract in 5 ml of xylene obeys Beer's law at saccharin concentrations between 20 and 400 µg ml–1. Cyclamates, sorbic acid, benzoic acid, 4-hydroxybenzoic acid and dehydroacetic acid do not interfere. Recoveries of saccharin from soft drinks were satisfactory. A procedure suitable for routine use is proposed.

Aliphatic diazo compounds. X. The reaction of α-diazoacetophenone with methanolic sodium methoxide

Abstract: The reaction of α-diazoacetophenone (1) with methanolic sodium methoxide in dilute solution gives 3-benzoyl-5-hydroxy-4-phenylpyrazole (4), 3-benzoyl-4-hydroxy-5-phenyl-pyrazole (5), 3-benzoyl-5-methoxy-4-phenylpyrazole (9), 3-benzoyl-4-phenylpyrazole (6), 5-benzoyltetrazole (7), 3,6-dibenzoyldihydro-s-tetrazine (10), cis- and trans- β-benzoyl- α-phenyl-acrylic acid, acetophenone, methyl benzoate, and benzoic acid. The pyrazoles 4, 5, and 9 are considered to arise via reaction of 1 to give α-methoxyacetophenone followed by further reaction of the anion of the latter with 1. Evidence in accord with this view was obtained by a study of the products formed when 1 was treated with methanolic sodium methoxide in the presence of 2-methoxy-4′-methylacetophenone. Acetophenone is considered to arise by reduction of 1 via phenylglyoxal 2-monohydrazone (37); condensation of 1 with the enolate ion derived from acetophenone then can give the pyrazole 6, while condensation of 1 with 37 could give the tetrazole 7.