Benzoic acid

About: Benzoic acid is a research topic. Over the lifetime, 11832 publications have been published within this topic receiving 167127 citations. The topic is also known as: Retardex & E210.

Anaerobic degradation of toluene in denitrifying Pseudomonas sp.: indication for toluene methylhydroxylation and benzoyl-CoA as central aromatic intermediate.

Abstract: The anaerobic degradation of toluene has been studied with whole cells and by measuring enzyme activities. Cultures of Pseudomonas strain K 172 were grown in mineral medium up to a cell density of 0.5 g of dry cells per liter in fed-batch culture with toluene and nitrate as the sole carbon and energy sources. A molar growth yield of 57 g of cell dry matter formed per mol toluene totally consumed was determined. The mean generation time was 24 h. The redox balance between toluene consumed (oxidation and cell material synthesis) and nitrate consumed (reduction to nitrogen gas and assimilation as NH3) was 77% of expectation if toluene was completely oxidized; this indicated that the major amount of toluene was mineralized to CO2. It was tested whether the initial reaction in anaerobic toluene degradation was a carboxylation or a dehydrogenation (anaerobic hydroxylation); the hypothetical carboxylated or hydroxylated intermediates were tested with whole cells applying the method of simultaneous adaptation; cells pregrown on toluene degraded benzyl alcohol, benzaldehyde, and benzoic acid without lag, 4-hydroxybenzoate and p-cresol with a 90 min lag phase, and phenylacetate after a 200 min lag phase. The cells were not at all adapted to degrade 2-methylbenzoate, 4-methylbenzoate, o-cresol, and m-cresol, nor did these compounds support growth within a few days after inoculation with cells grown on toluene. In extracts of cells anaerobically grown on toluene, benzyl alcohol dehydrogenase, benzaldehyde dehydrogenase, and benzoyl-CoA synthetase (AMP forming) activities were present. The data (1) conclusively show anaerobic growth of a pure culture on toluene; (2) suggest that toluene is anaerobically degraded via benzoyl-CoA; (3) imply that water functions as the source of the hydroxyl group in a toluene methylhydroxylase reaction.

Iridium-Catalyzed ortho-Arylation of Benzoic Acids with Arenediazonium Salts

Abstract: In the presence of catalytic [{IrCp*Cl2 }2 ] and Ag2 CO3 , Li2 CO3 as the base, and acetone as the solvent, benzoic acids react with arenediazonium salts to give the corresponding diaryl-2-carboxylates under mild conditions. This C-H arylation process is generally applicable to diversely substituted substrates, ranging from extremely electron-rich to electron-poor derivatives. The carboxylate directing group is widely available and can be removed tracelessly or employed for further derivatization. Orthogonality to halide-based cross-couplings is achieved by the use of diazonium salts, which can be coupled even in the presence of iodo substituents.

Mechanism of action of benzoic acid on Zygosaccharomyces bailii: effects on glycolytic metabolite levels, energy production, and intracellular pH.

Abstract: The effects of benzoic acid in the preservative-resistant yeast Zygosaccharomyces bailii were studied. At concentrations of benzoic acid up to 4 mM, fermentation was stimulated and only low levels of benzoate were accumulated. Near the MIC (10 mM), fermentation was inhibited, ATP levels declined, and benzoate was accumulated to relatively higher levels. Intracellular pH was reduced but not greatly. Changes in the levels of metabolites at different external benzoic acid levels showed that glycolysis was limited at pyruvate kinase and glyceraldehyde dehydrogenase-phosphoglycerate kinase steps. Inhibition of phosphofructokinase and several other glycolytic enzymes was not responsible for the inhibition of fermentation. Instead, the results suggest that the primary action of benzoic acid in Z. bailii is to cause a general energy loss, i.e., ATP depletion.