An analytical method using pentafluorobenzyl bromide (PFBB) derivatization and gas chromatography/mass spectrometry (GC/MS) has been applied to identify and quantify chloro-, bromo- and dichlorophenols in air, water and sediment samples. Phenols in air sample were collected with a PS-2 Sep-PAK cartridge, and eluted with 2-propanol. For water and sediment samples, liquid-liquid extraction with d...

Quantitative structure-activity relationships (QSARs) for prediction of the reaction rate constants of phenols and phenolates with three photochemically produced oxidants, singlet oxygen, carbonate radical, and triplet excited state sensitizers/organic matter, are developed. The predictive variable is the one-electron oxidation potential (E1), which is calculated for each species using density ...

Bisphenol A (BPA) and alkylphenols (APs) are well-known endocrine disrupting chemicals (EDCs) which may threat the next generations' health. We performed biomonitoring of these phenols in colostrums to assess risk of the phenols in breast-fed neonates. Study subjects were the lactating mothers who delivered babies within 2 weeks (N = 325; 30.67 ± 3.45 years) and their neonates (N = 326; embryon...

The objective of this investigation was to find a simple method for the production of phenolic rich products and sugar derivatives (biopolyols) via separation of liquefied lingocellulosic materials. Liquefaction of lignocellulosic materials was conducted in methanol at 180 °C for 15 min with the conversion of raw materials at about 75%. After liquefaction, the liquefied products were separated ...

Citation: Vera-Reyes I, Huerta-Heredia AA, Ponce-Noyola T, Cerda-García-Rojas CM, Trejo-Tapia G and Ramos-Valdivia AC (2015) Monoterpenoid indole alkaloids and phenols are required antioxidants in glutathione depleted Uncaria tomentosa root cultures. Front. Environ. Sci. 3:27. doi: 10.3389/fenvs.2015.00027 Monoterpenoid indole alkaloids and phenols are required antioxidants in glutathione deple...

[Ru(p-cymene)Cl2]2-catalyzed 1,4-addition reactions between arylboronic acids and butyl acrylate and acrylamide in the presence of phenols were investigated, good to excellent yields were obtained. The addition of phenols remarkably promoted the protonolysis and inhibited the β-H elimination of the 1,4-addition intermediates, and also efficiently suppressed the protonolysis of arylboronic acids.

The oxidation of phenols by HFeO4(-) proceeds via a hydrogen atom transfer (HAT) mechanism, as evidenced by a large deuterium isotope effect and a linear correlation between the log(rate constant) and bond dissociation free energy (BDFE) of phenols. The Marcus cross relation has been applied to predict the rate constant of HAT from hydroquinone to HFeO4(-).

A combination of ruthenium and photoredox catalysis allowed the ortho olefination of phenols. Using visible light, the direct C-H functionalization of o-(2-pyridyl)phenols occurred, and diverse phenol ethers were obtained in good yields. The regeneration of the ruthenium catalyst was accomplished by a photoredox-catalyzed oxidative process.

introduction: increasing of food-related diseases has led to the perception of diet importance. plant-derived products (especially tea) as important sources of antioxidant and antimicrobial compounds play a major role in reducing food pathogens. in this study, total phenolic content, antioxidant and antimicrobial activity of four tea extracts including green tea, white, black and red teas were ...