in this work, the study of various substituted kaempferol derivatives is presented. the bond dissociation energies (bde) have been calculated using b3lyp level and different basis sets in gas-phase. calculated results show that the bde values of substituted kaempferol range from about 77 to100 kcal/mol, demonstrating that kaempferol is an effective chain-breaking antioxidant that prevents lipid...

In this communication we draw attention on serious flaws that plague recently reported antioxidant properties of atorvastatin (ATV) in methanol. First and foremost, emphasize the O-H bond dissociation energies (BDE) about 400 kcal/mol previously are completely wrong. Further, present results refuting previous claim proton affinity (PA) ATV is smaller than ascorbic acid. That unfounded relies in...

To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7-O-β-glucoside with IC50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 ...

Experimental studies of the "extended toxicity" of substituted phenols are mainly of two types: the toxicity due to phenoxyl radical formation and the toxicity caused by metabolites, for example, the formation of quinones. Quantitative structure-activity relationship (QSAR) studies of phenol toxicity have dealt with the formation of phenoxyl radicals using bond dissociation enthalpy (BDE) of pa...

Phytophenols such as para-substituted 2-methoxyphenols exhibit antioxidant and anti-inflammatory activities, however, their biological activities are concentration-dependent, possibly due to their dual property of being both antioxidant and prooxidant. Eugenol (2-allyl-2-methoxyphenol) and isoeugenol (4-propenyl-2-methoxyphenol) did not reveal cyclooxygenase-2 (COX-2)-inhibiting activity in mac...

The structural modification of the resveratrol scaffold is currently an active issue in the quest for more potent and versatile antioxidant derivatives for biomedical applications. Disclosed herein is an expedient and efficient entry to a novel class of resveratrol derivatives featuring an unprecedented 2-phenylbenzoselenophene skeleton. The new compounds were obtained in good yields by direct ...

The potential for improving the stability of trinitramide (N(NO2)3) by chemical substitution NO2 group has been investigated using Kohn-Sham density functional theory [M06-2X/6-31+G(d,p)] and ab initio quantum chemistry [CBS-QB3]. Monosubstituted analogs are generally found to have a decreased N-NO2 bond dissociation enthalpy (BDE) because increased stabilization N(NO2)X radical intermediate re...

This paper reports an investigation of the oxidation three epoxy-amine networks obtained from DGEBA cured with sorts aliphatic hardeners ethylene diamine (EDA), diethylene triamine (DETA), and triethylene tetraamine (TETA). Oxidation was monitored by FTIR innovative discussion CH2 consumption. Methylene groups held were shown to be more sensitive oxidation, which confirmed a Bond Dissociation E...

Thermodynamic properties of phosphorus-containing compounds were investigated using high-level ab initio computations. An extended set of contemporary density functional theory (DFT) procedures was assessed for their ability to accurately predict bond dissociation energies of a set of phosphoranyl radicals. The results of meta- and double-hybrids as well as more recent methods, in particular M0...

With the aim of understanding the basis for the high rate of hydrogen atom abstraction (HAT) from dihydroanthracene (DHA) by the complex LCuOH (1; L = N,N'-bis(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamide), the bond dissociation enthalpy of the reaction product LCu(H2O) (2) was determined through measurement of its pK(a) and E(1/2) in THF solution. In so doing, an equilibrium between 2 and ...