The phenols of Paul's Scarlet rose stems and stem-derived cell cultures have been analyzed using C(18)-reversed-phase high performance liquid chromatography.Rose stems were found to contain gallic acid, (+)catechin, (-)epicatechin, the dimers (-)epicatechin-(+)catechin and (+)catechin-(+)catechin, a polymeric procyanidin, ferulic acid, and several gallotannins. In contrast, a cell suspension of...

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive...

The iodination of chlorinated aromatic compounds using Ag(2)SO(4)/I(2), AgSbF(6)/I(2), AgBF(4)/I(2) and AgPF(6)/I(2) offers access to iodoarenes that are valuable intermediates in organic synthesis. Specifically, iodination of phenols, anisoles and anilines with a 3,5-dichloro substitution pattern preferentially yielded the ortho, para and para iodinated product, respectively. In the case of ch...

We have found that bromo(triphenylphosphine)copper(I), an air-stable and soluble copper(I) complex, can be used as a catalyst in the synthesis of diaryl ethers. Using this catalyst, we have synthesized diaryl ethers from electron-rich aryl bromides and electron-rich phenols in the presence of cesium carbonate, in 17–24 h, in NMP. We also found that electron-deficient aryl bromides couple with p...

Nine long-chain phenols: four cardanols (1-4), two bilobols (5, 6) and three alkylsalicylic acids (7-9) [corrected] were isolated from the CH(2)Cl(2) extracts of the sarcotestas of Ginkgo biloba as HIV-1 protease (PR) inhibitors. From these phenols, the bilobols (IC (50), 2.6 - 5.8 microM) and alkylsalicylic acids (IC (50), 10.2 - 24.9 microM) exhibited dose-dependent potent inhibitory activiti...

In an attempt to understand the structural characteristics of phenolic compounds that favour the inhibition of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation, this study analyzes the role of twenty-five phenolic compounds on the PhIP produced in phenylalanine/creatinine/oxidised lipid reaction mixtures. The results showed that phenols having two hydroxy groups at meta position...

A gas chromatograph-mass spectrometer was used in an attempt to achieve rapid separation and accurate identification of benzo(a)pyrene and its synthesized derivatives. All derivatives, after being trimethylsilylated, were developed on Dexsil-300 and OV-1 columns. The seven diols and four stereoisomeric 7,8,9,10-tetraols studied were separated successfully. The separation of the 12 phenols was u...

1. Under defined conditions, the hydroxylation of p-coumaric acid catalysed by a phenolase from leaves of spinach beet (Beta vulgaris L.) was observed to develop its maximum rate only after a lag period. 2. By decreasing the reaction rate with lower enzyme concentrations or by increasing it with higher concentrations of reductants, the length of the lag period was inversely related to the maxim...

The influence of phenol and its derivatives on the kinetics of oxidation of aryldiamines (indicator-substrates) catalyzed by novel plant peroxidase-cationic peanut peroxidase-was studied. The character of influence of phenols on the kinetics of enzymatic oxidation of benzidine, o-dianisidine, and 3,3',5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide was found to depend on a correlation be...

1H- and 19F-NMR measurements of spin-lattice (T1) and spin-spin (T2) relaxationtimes and diffusion ordered spectroscopy (DOSY) were applied to investigate the association of nonsubstituted (phenol (P)) and halogen-substituted (2,4-dichlorophenol (DCP); 2,4,6-trichlorophenol (TCP), and 2,4,6-trifluorophenol (TFP) phenols with a dissolved humic acid (HA). T1 and T2 values for both 1H and 19F in p...