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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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Journal ArticleDOI
TL;DR: The first generation and spectroscopic identification of the higher-lying E conformer of the simplest aromatic carboxylic acid, benzoic acid (1a), as its O-deuterated isotopologue (E)-d(1)-1a using matrix-isolation techniques and the first Hammett relationships for atom tunneling are derived.
Abstract: We present the first generation and spectroscopic identification of the higher-lying E conformer of the simplest aromatic carboxylic acid, benzoic acid (1a), as its O-deuterated isotopologue (E)-d1...

57 citations

Journal ArticleDOI
TL;DR: In this article, tetramethylammonium hydroxide (TMAH) was applied to the analysis of red dyes based on the 9,10-anthracenedione skeleton (anthraquinone).

57 citations

Journal ArticleDOI
TL;DR: The interaction of substrates with a 4-methoxybenzoate O-demethylating enzyme system was studied by use of crude cell-free extracts and by the purified enzyme system, which requires NADH and oxygen as cofactors and acts on various substrates.
Abstract: The interaction of substrates with a 4-methoxybenzoate O-demethylating enzyme system was studied by use of crude cell-free extracts and also by the purified enzyme system. The two components of the enzyme system, an iron-containing flavoprotein and an iron-sulphur protein, were obtained in pure state from Pseudomonas putida grown on 4-methoxybenzoate as the sole carbon source. The purified enzyme system requires NADH and oxygen as cofactors and acts on various substrates. The highest affinity is found for 4-methoxybenzoate, but also N-methyl-4-aminobenzoate is demethylated and 4-alkylbenzoates are hydroxylated at the side chain. The enzyme is rather specific for para-substituted benzoic acid derivatives whereas 3-methoxybenzoate and 4-hydroxy-3-methoxybenzoate are demethylated slowly. The enzyme is also able to hydroxylate the aromatic ring. This is shown by the isolation of 3,4-dihydroxybenzoate as the hydroxylation product of 3-hydroxy- or 4-hydroxy-benzoate, respectively. Studies on substrate binding and oxygen consumption with substrate analogues showed an absolute requirement for the carboxy group at the aromatic ring. Benzoic acid derivatives without a suitable CH-bond uncouple oxygen uptake with a concomitant formation of hydrogen peroxide. Measurements of oxygen consumption indicate that the affinity towards oxygen is substrate dependent, probably due to steric alterations as a consequence of substrate binding.

57 citations

Journal ArticleDOI
TL;DR: Retinoic acid, 7, 13, 14, and 19 inhibited papilloma tumor formation in mice, and toxicity testing indicated that 7 was more toxic than 1, 13 and 14 were less toxic than 2, and 13 and 13 were less Toxic than 1.
Abstract: A series of conformationally restricted retinoids was synthesized and screened in two assays used to measure the ability of retinoids to control cell differentiation, namely, the reversal of keratinization in tracheal organ culture from vitamin A deficient hamsters and the inhibition of the induction of mouse epidermal ornithine decarboxylase by a tumor promoter. These compounds had bonds corresponding to selected bonds of the E-tetraene chain of retinoic acid (1) held in a planar cisoid conformation by inclusion in an aromatic ring. The meta-substituted analogue 3 of 4-[(E)-2-methyl-4-(2,6,6-trimethylcyclohexenyl)-1,3-butadienyl+ ++]benzoic acid (2) was far less active than 2 in both assays. In contrast, the vinyl homologue of 2 (4) and the 7,8-dihydro and 7,8-methano analogues (5 and 6) had activity comparable to that of 2. Analogues of 4-[(E)-2-(1,1,4,4-tetramethyl-1,2,3,4-tetrahydro-6-naphthyl)propenyl] benzoic acid (7) were also screened. Replacement of the tetrahydronaphthalene ring of 7 by a benzonorbornenyl group (9) significantly reduced activity, as did removal of the vinylic methyl group from 9 (10). Replacement of the propenyl group of 9 by a cyclopropane ring (12) also reduced activity. Replacement of the tetrahydronaphthalene ring of 7 by 4,4-dimethyl-3,4-dihydro-2H-1-benzopyran and -benzothiopyran rings (13 and 14) also decreased activity. Inclusion of the 7,9 double bond system of 1 in an aromatic ring (15 and 16) reduced activity, whereas inclusion of the 5,7 double bond system in an aromatic ring enhanced activity (7 and 19). Inclusion of the 11,13 and 9,11,13 double bond systems in aromatic rings (2 and 18) also reduced activity below that of 1. Retinoic acid, 7, 13, 14, and 19 inhibited papilloma tumor formation in mice. Toxicity testing indicated that 7 was more toxic than 1, 13, 14, and 19, 19 was more toxic than 1, and 13 and 14 were less toxic than 1.

57 citations

Journal ArticleDOI
TL;DR: A general scheme for obtaining a fluorescent donor/acceptor peptide substrate via solid-phase synthesis methodology is presented and substrates for renin and HIV proteinase are synthesized as examples.
Abstract: A general scheme for obtaining a fluorescent donor/acceptor peptide substrate via solid-phase synthesis methodology is presented. The key feature of this method is the design of a glutamic acid derivative that has been modified on the carboxyl side chain with a 5-[(2'-aminoethyl)-amino]naphthelenesulfonic acid (EDANS) to create a fluorescent donor moiety that can be incorporated near the C-terminus of the peptide substrate. The corresponding fluorescent acceptor group containing a 4-[[4-(dimethylamino)phenyl]azo]benzoic acid (DABCYL) can then be attached to the resin-bound peptide at the N-terminus while all side-chain groups are still fully protected. Substrates for renin and HIV proteinase are synthesized as examples.

57 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023207
2022519
2021217
2020279
2019315
2018332