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Simple Phenols (simple + phenol)
Selected AbstractsInhibition of lipid peroxidation by anthocyanins, anthocyanidins and their phenolic degradation productsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 1 2007Jonathan E. Brown Abstract Food components that delay or prevent biomolecule oxidation may be relevant in shelf life extension as well as disease prevention. Anthocyanins are a potentially important group of compounds, but they are prone to degradation both in vitro and in vivo, producing simple phenols. In this study, eight structurally related (poly)phenols [anthocyan(id)ins and phenolic acids] were examined for their ability to inhibit lipid oxidation at physiologically relevant concentrations (100,1000,nM) using the Cu2+ -mediated low-density lipoprotein oxidation model. Interaction between each (poly)phenol and Cu2+ ions was also investigated. (Poly)phenols with an ortho -dihydroxy group arrangement, i.e. cyanidin-3-glucoside, cyanidin and protocatechuic acid, were the most effective within their class, extending the lag phase to oxidation by 137, 255 and 402%, respectively (at 1000,nM). At the same concentration, trihydroxy-substituted compounds (delphinidin and gallic acid) were of intermediate efficacy, extending the lag phase by 175 and 38%, respectively. Compounds with the 4'-hydroxy-3',5'-methoxy arrangement (i.e. malvidin-3-glucoside and malvidin) were the least effective (3 and 58% extension, respectively), while syringic acid (4-hydroxy-3,5-dihydroxy benzoic acid) was pro-oxidant (lag phase shortened by 31%). (Poly)phenols with the ortho -dihydroxy arrangement chelated Cu2+ ions, which in part explains their greater efficacy over the other (poly)phenols in this model oxidation system. However, differences in their hydrogen-donating properties and their partitioning between lipid and hydrophilic phases are also relevant in explaining these structure-activity relationships. [source] 2-Substituted Benzo[b]furans from (E)-1,2-Dichlorovinyl Ethers and Organoboron Reagents: Scope and Mechanistic Investigations into the One-Pot Suzuki Coupling/Direct Arylation,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2010Laina M. Geary Abstract 2-Substituted benzo[b]furans can easily be assembled from simple phenols, boronic acids or other organoboron reagents, and trichloroethylene. The overall process requires only two synthetic steps, with the key step being a one-pot sequential Suzuki cross-coupling/direct arylation reaction. The method tolerates many useful functional groups and does not require the installation of any other activating functionality. The modular nature of the process permits the rapid synthesis of many analogues using essentially the same chemistry, of particular value in drug development. Results of kinetic isotope effect studies and investigations into the regioselectivity of the process indicate that the direct arylation step most likely does not involve an electrophilic palladation. The most likely mechanism lies somewhere on the continuum between a C,H bond metathesis and an assisted palladation or concerted metallation-deprotonation pathway. [source] Characterization of a novel silkworm (Bombyx mori) phenol UDP-glucosyltransferaseFEBS JOURNAL, Issue 3 2002Teresa Luque Sugar conjugation is a major pathway for the inactivation and excretion of both endogenous and exogenous compounds. We report here the molecular cloning and functional characterization of a phenol UDP-glucosyltransferase (UGT) from the silkworm, Bombyx mori, which was named BmUGT1. The complete cDNA clone is 1.6 kb, and the gene is expressed in several tissues of fifth-instar larvae, including fat body, midgut, integument, testis, silk gland and haemocytes. The predicted protein comprises 520 amino acids and has ,,30% overall amino-acid identity with other members of the UGT family. The most conserved region of the protein is the C-terminal half, which has been implicated in binding the UDP-sugar. BmUGT1 was expressed in insect cells using the baculovirus expression system, and a range of compounds belonging to diverse chemical groups were assessed as potential substrates for the enzyme. The expressed enzyme had a wide substrate specificity, showing activity with flavonoids, coumarins, terpenoids and simple phenols. These results support a role for the enzyme in detoxication processes, such as minimizing the harmful effects of ingested plant allelochemicals. This work represents the first instance where an insect ugt gene has been associated with a specific enzyme activity. [source] Isolation and Characterization of Virgin Olive Oil Phenolic Compounds by HPLC/UV and GC-MSJOURNAL OF FOOD SCIENCE, Issue 4 2001M. Tasioula-margari ABSTRACT This research examined the phenolic fraction of extra virgin olive oil samples from Lianolia variety olives grown in the region of Preveza, Greece. Phenolic compounds were extracted from oil samples, separated by reversed-phase high-performance liquid chromatography (HPLC), and characterized by gas chromatography-mass spectrometry (GC-MS). Both simple and complex phenols were detected with the latter being the most abundant. 3,4-Dihydroxyphenyl ethanol (hydroxytyrosol) and p-hydroxyphenylethanol (tyrosol) predominated among the simple phenols. Complex phenolic compounds were further separated by preparative HPLC and analyzed by GC-MS before and after hydrolysis. The presence of hydroxytyrosol and tyrosol derivatives was confirmed. Both derivatives were always present in greater quantities and made up an average exceeding 70% in all samples analyzed. [source] Chromatographic analysis of simple phenols in some species from the genus SalixPHYTOCHEMICAL ANALYSIS, Issue 5 2010Loretta Pob, ocka-Olech Abstract Introduction , Salicis Cortex, made from willow bark is a herbal remedy, which is standardised based on the content of salicin, a compound with analgesic and antiphlogistic properties. However, clinical trials suggest that other compounds also present in Salicis Cortex can contribute to the pharmacological effects. Objective , To characterise the composition of phenolic acids in the barks of different species and clones from the genus Salix by use of chromatographic methods,HPTLC and HPLC. Methodology , The phenolic acid composition was analysed by MGD (multiple gradient development),HPTLC technique. The separation was performed on HPTLC Diol plates with gradient elution using a mixture of chloroform:hexane:ethyl acetate with increasing concentration of ethyl acetate from 10 to 25%. Derivatisation with thymol reagent was employed for the first time for specific detection of phenolic acids containing methoxyl groups. Results , The presence of all phenolic acids previously reported in the genus Salix was confirmed, namely p -hydroxybenzoic, vanillic, cinnamic, p -coumaric, ferulic and caffeic acids. Furthermore, pyrocatechol as a constituent of willow bark was revealed. The highest concentration of this compound was observed in the S. purpurea bark (2.25,mg/g). Conclusion , The presence of a relatively high content of pyrocatechol in Salix species may raise doubts about the safe application of this herbal medicine. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||