Quantum chemical calculations at the B3LYP/6-31G* level of theory were employed for the structure-activity relationship and prediction of the antioxidant activity of edaravone and structurally related derivatives using energy (E), ionization potential (IP), bond dissociation energy (BDE), and stabilization energies (ΔE(iso)). Spin density calculations were also performed for the proposed antiox...

Antioxidant capacity is the extent to which a compound can eliminate reactive oxygen species, and in vitro methods for its chemical evaluation have been proposed. Among these methods, radical absorbance (ORAC) assay comes close oxidation reaction living body because it generates species that mimic lipid peroxyl involved peroxidation of biological components react phosphate buffer. In this study...

Isoelectronic C=F(+) and C=O bonds contained in fluoro-substituted carbenium ions, aldehydes, and ketones are investigated with regard to their bond properties by utilizing the vibrational spectra of these molecules. It is demonstrated that bond dissociation energies (BDEs), bond lengths, vibrational stretching frequencies, and bond densities are not reliable descriptors of the bond strength. T...

The recently discovered lignin composed of caffeoyl alcohol monolignols or C-lignin is particularly intriguing given its homogeneous, linear polymeric structure and exclusive benzodioxane linkage between monomers. By virtue of this simplified chemistry, the potential emerges for improved valorization strategies with C-lignin relative to other natural heterogeneous lignins. To better understand ...

Quantum-chemical computations were used to investigate the structure-antioxidant parameter relationships of α-lipoic acid and its natural metabolites bisnorlipoic acid and tetranorlipoic acid in their oxidized and reduced forms. The enantiomers of lipoic and dihydrolipoic acid were optimized using the B3LYP/6-311+G(3df,2p), B3LYP/aug-cc-pVDZ and MP2(full)/6-31+G(d,p) levels of theory as isolate...

BACKGROUND Brominated flame retardants, including the widely used polybrominated diphenyl ethers (PBDEs), have been detected in humans, raising concern about possible neurotoxicity. Recent research demonstrated that the hydroxylated metabolite 6-OH-BDE-47 increases neurotransmitter release by releasing calcium ions (Ca2+) from intracellular stores at much lower concentrations than its environme...

BACKGROUND Previous studies have shown that polybrominated diphenyl ethers (PBDEs) behave as weak estrogens in animal and cell culture bioassays. In vivo metabolites of PBDEs are suspected to cause these effects. OBJECTIVES To identify candidate metabolites, mouse plasma samples were collected after continuous oral and subcutaneous exposure to DE-71, a widely used commercial pentabromodipheny...

Employing pure water, the ultimate green source of hydrogen donor to initiate chemical reactions that involve a atom transfer (HAT) step is fascinating but challenging due its large H-O bond dissociation energy (BDE = 5.1 eV). Many approaches have been explored stimulate water for hydrogenative reactions, efficiency and productivity still require significant enhancement. Here, we show surface h...

The oxygen–oxygen bond dissociation enthalpies in di-tert-butyl peroxide (Me3CO–OCMe3) and di-trifluoromethyl peroxide (F3CO– OCF3) were determined using MP2, the hybrid functional B3LYP, and the CBS-QB3 method. Comparison of the performances of these methods, with particular emphasis on extrapolation procedures to infinite basis-set, showed that only CBS-QB3 is suitable for the accurate calcul...

The enthalpy of hydrolysis of the 3’-bond of several cyclic 3’,5’-nucleotides and of the 2’-bond of several cyclic 2’,3’nucleotides has been measured calorimetrically. In each case, the enthalpy was indicative of a high energy bond, although values for different compounds varied from -7.7 to 14.1 kcal mole-‘. The enthalpy of hydrolysis of the cyclic 3’,5’-nucleotides, but not that of the cyclic...