Hammett constants (σ) can be important factor to understanding substitution and position effects on benzoic acid. This report describes a computational study of ∆G◦ and σ for six substituted benzoic acid (X= F,Cl ,OH ,NH2 ,CN,NO2 )and phenylacetic acid substituted (X=OH ,NH2 ) at para and meta positions ingas and aqueousphases by DFT method and comparesit to available experimental and theoretic...

The pKAH-values of some substituted phenylacetic acid derivatives have been determined in the system water /dimethyl sulphoxide / 0. 11 M tetramethylammonium hydroxide. The acidity depends strongly on the polarity of the substituent in the phenyl group, Hammett p-valucs from 4.8 to 5 .8, and in the case of the same s<1bstituent decreasf's in the order nit! ik, terr-butyl ester, dimethylami<'e e...

Acid dissociation constant (pKa) of some para-substituted benzohydroxamic, 4-XC6H4CONHOH, and N-methyl parasubstituted benzohydroxamic acids, 4XC6H4CON(OH)CH3, where X = H, CH3, CH3O, NO2, Cl, have been determined spectrophotometrically by nucleophilic substitution reactions of pnitrophenyl acetate with hydroxamate ions at 27± 0.1C. All reactions in this study follow pseudo-first order kinetics...

Substituent effects on the physical properties and pKa of phenol were studied using density functional theory [B3LYP /6-311G(d,p)] calculations. Substituents alter the physical properties of phenol such as the hydroxyl-group C-0 and 0-H bond lengths, the C-0-H bond angle, and the energy barrier to rotation about the C-0 bond, and also influence the hydroxyl-group pK •. Except for the rotational...

The effects of substituents on the pKas of a set of 16 substituted benzoic acids have been examined using density functional theory [B3LYP/6-311G(d, p)] calculations. A variety of quantum chemical parameters were examined as indicators for the variations observed in the experimental pKas, including the Löwdin, Mulliken, AIM, and natural population analysis charges (QL, QM, QA, and Qn) on atoms ...

Penicillium chrysogenum utilizes phenylacetic acid as a side chain precursor in penicillin G biosynthesis. During industrial production of penicillin G, phenylacetic acid is fed in small amounts to the medium to avoid toxic side effects. Phenylacetic acid is taken up from the medium and intracellularly coupled to 6-aminopenicillanic acid. To enter the fungal cell, phenylacetic acid has to pass ...

Penicillin acylase catalyses the condensation of Calpha-substituted phenylacetic acids with beta-lactam nucleophiles, producing semi-synthetic beta-lactam antibiotics. For efficient synthesis a low affinity for phenylacetic acid and a high affinity for Calpha-substituted phenylacetic acid derivatives is desirable. We made three active site mutants, alphaF146Y, betaF24A and alphaF146Y/betaF24A, ...

Background: For understanding the roles of fatty acids on the induction of acrosome reaction which occurs under association of cholesterol efflux and PKA or PKC pathways in boar spermatozoa, metabolic fate of alone and combined radiolabeled 14C-oleic acid and 3H-linoleic acid incorporated in the sperm was compared, and behavior of cholesterol and effects of PKA and PKC inhibitors upon fatty aci...

OBJECTIVES To determine in this pilot study whether aerobic exercise affects phenylacetic acid concentration in the urine. METHODS Twenty healthy men provided 24 hour urine samples on two consecutive days for the determination of phenylacetic acid levels. Before and during day 1, subjects refrained from physical activity; on day 2 subjects ran on a treadmill at 70% of their maximal heart rate...

Here, we focused on a simple enzymatic epoxidation of alkenes using lipase and phenylacetic acid. The immobilised Candida antarctica lipase B, Novozym 435 was used to catalyse the formation of peroxy acid instantly from hydrogen peroxide (H2O2) and phenylacetic acid. The peroxy phenylacetic acid generated was then utilised directly for in situ oxidation of alkenes. A variety of alkenes were oxi...