Electrostatic potentials and average local ionization energies on the molecular surfaces of 19 phenols, 17 benzoic acids and their respective conjugate bases were computed at the HF/STO-5G(d)//B3LYP/6311G(d,p) level. Good correlations were found between pKas and the VS,max values of the neutral acids and the VS,min and IS;min of the conjugate bases for both sets of molecules. VS,max is the most...

Outbreaks of disease due to vegetative bacterial pathogens associated with acid foods (such as apple cider) have raised concerns about acidified vegetables and related products that have a similar pH (3.2 to 4.0). Escherichia coli O157:H7 and related strains of enterohemorrhagic E. coli (EHEC) have been identified as the most acid resistant vegetative pathogens in these products. Previous resea...

Studies have been carried out, using the toad bladder, to determine the influence of pH on the permeability coefficients (K(trans)) of the non-ionic species of (a) a series of aliphatic acids ranging from propionic to octanoic and (b) the aromatic acids, benzoic and acetylsalicylic. The data demonstrate that as the acidity of the mucosal bathing solution is increased by changing pH from 6 to 4,...

The PM6 semiempirical method and the dispersion and hydrogen bond-corrected PM6-D3H+ method are used together with the SMD and COSMO continuum solvation models to predict pKa values of pyridines, alcohols, phenols, benzoic acids, carboxylic acids, and phenols using isodesmic reactions and compared to published ab initio results. The pKa values of pyridines, alcohols, phenols, and benzoic acids ...

Seven phenolic acids and many nonphenolic organic acids, including large amounts of meta-hydroxy (3-hydroxy) benzoic acid and 3-hydroxy-1,5-benzene-dicarboxylic acid, were obtained from the organic polymer of the Murchison C2 chondrite upon oxidation with alkaline cupric oxide. The phenolic acids apparently were derived from phenolic ethers in the polymer, which in turn probably were formed fro...

Shikimic acid and its role in the formation of aromatic amino acids, benzoic acids, and cinnamic acids is described, along with further modifications leading to lignans and lignin, phenylpropenes, and coumarins. Combinations of the shikimate pathway and the acetate pathway are responsible for the biosynthesis of styrylpyrones, flavonoids and stilbenes, flavonolignans, and isoflavonoids. Terpeno...