Topic
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.
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TL;DR: It is proposed here that the degree of reactivity of acyl glucuronides as measured by covalent binding to protein is proportional to the amount of its peptide adduct generated with the peptide technique described, and developed a reactivity rank of seven carboxylic acid-containing drugs.
Abstract: A novel technique to study the reactivity of acyl glucuronide metabolites to protein has been developed and is described herein. Considered here are acyl glucuronide metabolites, which have undergone the rearrangement of the glucuronic acid moiety at physiological temperature and pH. The investigation of the reactivity of these electrophilic metabolites was carried out by measuring the rate of reaction of rearranged AG metabolites in forming the corresponding acyl glucuronide-peptide adduct in the presence of Lys-Phe. This differs from the parallel technique used in forming AG adducts of proteins that have been previously reported. In the study described here, the Schiff base adduct, diclofenac acyl glucuronide-Lys-Phe product, was generated and structurally elucidated by liquid chromatography tandem mass spectrometry (LC/MS/MS) analysis. The product structure was proved to be a Schiff base adduct by chemical derivatization by nucleophilic addition of HCN and chemical reduction with NaCNBH(3), followed by LC/MS/MS analysis. It is proposed here that the degree of reactivity of acyl glucuronides as measured by covalent binding to protein is proportional to the amount of its peptide adduct generated with the peptide technique described. The application of this technique to the assessment of the degree of reactivity of acyl glucuronide metabolites was validated by developing a reactivity rank of seven carboxylic acid-containing drugs. Consistency was achieved between the ranking of reactivity in the peptide technique for these seven compounds and the rankings found in the literature. In addition, a correlation (R(2) = 0.95) was revealed between the formation of a peptide adduct and the rearrangement rate of the primary acyl glucuronide of seven tested compounds. A structure effect on the degree of reactivity has demonstrated the rate order: acetic acid > propionic acid > benzoic acid derivatives. A rational explanation of this order was proposed, based on the inherent electronic and steric properties of each specific aglycone. In addition, adaptation of this technique to automation in order to more rapidly assess the ranking of reactivity of acyl glucuronide covalent binding to proteins by new chemical entities is proposed.
71 citations
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TL;DR: In this paper, the authors attribute the tight product control to mainly two factors: access to the C{sub 6}H{sub 5}CH{sub 3}-O{sub 2} excited charge transfer state by light of sufficiently long wavelength to prevent loss of product control by photofragmentation of primary products or by homolysis of the proposed hydroperoxide intermediate.
Abstract: High selectivity has been demonstrted upon visible light induced oxygenation of toluene to benzaldehyde in alkaline earth exchanged zeolite Y. We attribute the tight product control to mainly two factors. One is access to the C{sub 6}H{sub 5}CH{sub 3}-O{sub 2} excited charge-transfer state by light of sufficiently long wavelength to prevent loss of product control by photofragmentation of primary products or by homolysis of the proposed hydroperoxide intermediate. The second is confinement of benzyl/HO{sub 2} radical pairs to the zeolite matrix cage, which suppresses indiscriminate attack of these radicals and forces them to combine. The Co{sup 3+}-catalyzed radical oxidation of toluene by O{sub 2} in solution used currently in an industrial process for benzaldehyde synthesis lacks this selectivity, mainly because of continued oxidation of the aldehyde to benzoic acid. 24 refs., 2 figs.
71 citations
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TL;DR: In this paper, the effect of operating conditions such as temperature, catalyst to plastic mass ratio and volatiles residence time and their interactions on product yields and properties were studied, and it was shown that up to 27-32% benzoic acid could be recovered through PET pyrolysis at 450-600'C at 20's residence time.
71 citations
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TL;DR: The adsorption rate and the extent were found to be the highest at pH 3.7 and decreased at higher or lower pH values and the types of interactions governing in the Adsorption processes are discussed considering the surface charge and the dissociation of benzoic acid at different pH values.
71 citations
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TL;DR: The degradation to benzoic acid derivatives rather than phenylacetic acid derivatives seems to be a predominant route of metabolism in humans, and the results of this pilot study give rise to additional, substantial pharmacokinetic investigations in humans.
71 citations