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Carboxylic acid
About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.
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TL;DR: Two triterpene carboxylic acids, ursolic acid and oleanolic acid, have been isolated as inhibitors of 12-O-tetradecanoylphorbol-13-acetate induced Epstein-Barr virus activation in Raji cells, and enhancement of the inhibitory activity was found in 3-keto derivatives of UA and OA.
159 citations
TL;DR: In this article, the octanol-water distributions of 10 environmentally significant organic acid compounds were determined as a function of aqueous-phase salt concentration (0.05-0.2 M LiCl, NaCl, KCl, CaCl{sub 2}, or MgCl[sub 2}) and pH.
Abstract: The octanol-water distributions of 10 environmentally significant organic acid compounds were determined as a function of aqueous-phase salt concentration (0.05-0.2 M LiCl, NaCl, KCl, CaCl{sub 2}, or MgCl{sub 2}) and pH. The compounds were pentachlorophenol, 2,3,4,5-tetrachlorophenol, (2,4,5-trichlorophenoxy)acetic acid, 4-chloro-{alpha}-(4-chlorophenyl)benzeneacetic acid, 2-methyl-4,6-dinitrophenol, (2,4-dichlorophenoxy) acetic acid, 4-(2,4-dichlorophenoxy) butanoic acid, 3,6-dichloro-2-methoxybenzoic acid, 2,3,6-trichlorobenzeneacetic acid, and 2-(2,4,5-trichlorophenoxy)propionic acid. The experimental results were interpreted quantitatively with an equilibrium model that accounts for acid dissociation in the aqueous phase and partitioning into the octanol phase by the neutral organic species, free inorganic and organic ions, and ion pairs. The partition constants for the neutral ion pairs correlate well with the partition constants of the neutral acids. Two experiments address the applicability of these octanol-water distribution data to the distribution of ionogenic compounds in the environment: the distribution of 2-methyl-4,6-dinitrophenol on a natural sorbent as a function of salt concentration (NaCl and CaCl{sub 2}) and pH, and competitive adsorption of pentachlorophenol and 2,3,4,5-tetrachlorophenol on an environmental sorbent.
158 citations
TL;DR: A novel naphthyl-fused zinc porphyrin carboxylic acid has been synthesized and employed successfully in a dye-sensitized TiO2 solar cell, with a power conversion efficiency of 4.1%, which is improved by 50% relative to the unfused porphyrsin reference cell.
158 citations
TL;DR: Graphene sheets were covalently functionalized with aromatic-aliphatic amino acids (phenylalanine and tyrosine) by simple and green procedure as discussed by the authors, and Amino acid functionalized graphene demonstrates stable dispersion in water and common organic solvents.
158 citations
TL;DR: The pyrimidine ring is postulated as the molecule component essential for the toxicity of cylindrospermopsin.
Abstract: A new natural derivative of the sulfated guanidinium zwitterionic toxin cylindrospermopsin, 7-epi-cylindrospermopsin, was recently isolated from the cyanobacterium Aphanizomenon ovalisporum (Forti). The toxicity of the molecule (LD50 ip 5 d), estimated by mouse bioassay, was 200 µg/kg mouse, a value similar to that of cylindrospermopsin. Treatment of cylindrospermopsin with chlorine solution or chlorine-related oxidants produced two new derivatives. The chemical structure of these products was elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques and toxicity was determined. In the first derivative, the vinylic proton at position 5 of the pyrimidine ring was substituted by chlorine to yield 5-chlorocylindrospermopsin. The other product is a truncated one, where C-6 of the pyrimidine ring was oxidized to a carboxylic acid. A trivial name, cylindrospermic acid, was given to this compound. Both products showed no toxic effects even at doses 50 times higher than the LD50 of cyli...
158 citations