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.

Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae

Abstract: Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids, but the exact mechanism is still unknown. We set out to quantitatively determine the contributions of various mechanisms of antifungal activity of these weak acids, as well as the mechanisms that yeast uses to counteract their effects. We analyzed the effects of four weak organic acids differing in lipophilicity (sorbic, benzoic, propionic, and acetic acids) on growth and intracellular pH (pH(i)) in Saccharomyces cerevisiae. Although lipophilicity of the acids correlated with the rate of acidification of the cytosol, our data confirmed that not initial acidification, but rather the cell's ability to restore pH(i), was a determinant for growth inhibition. This pH(i) recovery in turn depended on the nature of the organic anion. We identified long-term acidification as the major cause of growth inhibition under acetic acid stress. Restoration of pH(i), and consequently growth rate, in the presence of this weak acid required the full activity of the plasma membrane ATPase Pma1p. Surprisingly, the proposed anion export pump Pdr12p was shown to play an important role in the ability of yeast cells to restore the pH(i) upon lipophilic (sorbic and benzoic) acid stress, probably through a charge interaction of anion and proton transport.

Activation of carbon dioxide by electron transfer and transition metals. Mechanism of nickel-catalyzed electrocarboxylation of aromatic halides

Abstract: In the presence of stoichiometric amounts of carbon dioxide, and catalytic amounts of Ni II (dppe)Cl 2 , electrolysis of bromobenzene results in the nearly quantitative formation of benzoic acid with negligible production of benzene or biphenyl. Based on a detailed kinetic analysis of the propagation of this catalytic chain and of its competition with the biphenyl chain, all the key steps of the catalytic chain are identified and their rate constants determined

Dimer or catemer? Low-energy crystal packings for small carboxylic acids

Abstract: The ability of a search for minima in the lattice energy to predict the crystal structures of three carboxylic acids was examined, using an ab initio based distributed multipole model for the dominant electrostatic contribution to the intermolecular forces. This model was combined with an empirical atom−atom potential with the polar hydrogen atom parameters specifically adjusted to reproduce a range of carboxylic acid crystal structures. The catemer structure of formic acid, the dimer-based structure of benzoic acid, and both the catemer and dimer polymorphs of tetrolic acid were found reasonably accurately, close to the global minimum in the lattice energy. However, as in the recently highlighted case of acetic acid, there are a variety of energetically competitive structures, with both the catemer and dimer motifs, for formic and tetrolic acid. In contrast, all low-energy structures for benzoic acid were based on the dimer motif. These hypothetical structures demonstrate the role of energetics in determ...