Search results for "PHENOLS"

Synthesis of No-Carrier-Added 4-[18F]Fluorophenol from 4-Benzyloxyphenyl-(2-thienyl)iodonium Bromide

2011

4-[(18)F]Fluorophenol is a versatile synthon for the synthesis of more complex radiopharmaceuticals bearing a 4-[(18)F]fluorophenoxy moiety. In order to prepare 4-[(18)F]fluorophenol in no-carrier-added (n.c.a.) form only a nucleophilic labelling method starting from [(18)F]fluoride is suitable. In this paper a new, two step radiosynthesis starting from 4-benzyloxyphenyl-(2-thienyl)iodonium bromide and [(18)F]fluoride with subsequent deprotection is described, yielding n.c.a. [(18)F]fluorophenol in 34 to 36% radiochemical yield.

Derivatization of hydroxyl functional groups for liquid chromatography and capillary electroseparation

2013

The derivatization reactions commonly used to enhance the analytical signal in the HPLC and CE determination of compounds with hydroxyl functional groups are revised. Focus is placed on the determination of compounds having aliphatic alcohols and phenols while lacking other reactive functional groups. The derivatization with acyl chlorides, organic anhydrides, isocyanates and a variety of other approaches, including oxidation of primary and secondary alcohols, sulfonation, esterification with carboxylic acids, and the use of azides, sulfonyl chlorides and other reagents having miscellaneous leaving groups, is covered. Reactions mainly addressed to introduce a chromophore or a fluorophore in…

THE USE OF LACTOBACILLUS PENTOSUS 1MO TO SHORTEN THE DEBITTERING PROCESS TIME OF BLACK TABLE OLIVES (CV. ITRANA AND LECCINO): A PILOT-SCALE APPLICATI…

2006

Fifty lactobacilli isolated from black table olive brines were evaluated for their salt tolerance, resistance to oleuropein and verbascoside, and ability to grow in modified filter-sterilized brines. A strain of Lactobacillus pentosus was selected and used as a starter to ferment, in pilot plant, black olives (Itrana and Leccino cv.) in brines modified for pH, carbohydrate, and growth factor concentrations, at 28 degrees C. The temperature-controlled fermentation of Leccino cv. olives resulted in obtaining ready-to-eat, high-quality table olives in a reduced-time process. HPLC analysis of phenolic compounds from fermented olives showed a decrease of oleuropein, a glucoside secoiridoid respo…

Bioavailability and metabolism.

2002

Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on …

2015

This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence.-- et al.

Study of chemical changes produced in virgin olive oils with different phenolic contents during an accelerated storage treatment.

2009

Chemical changes produced in an extra virgin olive oil sample in the presence (EVOO) and absence (EVOOP) of its phenolic fraction during an accelerated storage treatment at 60 degrees C up to 7 weeks were studied. Modifications in phenol content, as well as changes in several quality parameters (free acidity, peroxide value, UV absorbance, fatty acid composition, oxidative stability index, and tocopherol content) were also evaluated under the same storage conditions and compared to those of the same sample deprived of phenolic compounds. When the phenolic extract of the EVOO was studied, a decrease of the antioxidants first present in the sample and an increase of the oxidized products were…

Cork Taint of Wines: Role of the Filamentous Fungi Isolated from Cork in the Formation of 2,4,6-Trichloroanisole by O Methylation of 2,4,6-Trichlorop…

2002

ABSTRACT Cork taint is a musty or moldy off-odor in wine mainly caused by 2,4,6-trichloroanisole (2,4,6-TCA). We examined the role of 14 fungal strains isolated from cork samples in the production of 2,4,6-TCA by O methylation of 2,4,6-trichlorophenol (2,4,6-TCP). The fungal strains isolated belong to the genera Penicillium (four isolates); Trichoderma (two isolates); and Acremonium , Chrysonilia , Cladosporium , Fusarium , Mortierella , Mucor , Paecilomyces , and Verticillium (one isolate each). Eleven of these strains could produce 2,4,6-TCA when they were grown directly on cork in the presence of 2,4,6-TCP. The highest levels of bioconversion were carried out by the Trichoderma and Fusar…

Sensory-active compounds influencing wine experts' and consumers' perception of red wine intrinsic quality

2015

© 2014 Elsevier Ltd. There is a lack of studies focusing on the chemical compounds involved in quality perception. The present work combines both sensory and chemical approaches with the final goal of evaluating the sensory-active compounds influencing wine experts' and consumers' perception of red wine quality. Perceived quality was categorised by 108 consumers and 119 experts according to four levels going from very low to very high quality. In parallel, samples were described by a descriptive trained panel and volatile and non-volatile chemicals with known sensory activity were quantified. Wines with higher concentrations of eugenol, E- and Z-whiskylactones and 4-ethylphenol (discussed i…

Evaluation of antioxidant properties and assessment of genetic diversity of Capparis spinosa cultivated in Pantelleria Island.

2017

Capparis spinosa is a wild and cultivated bush, which grows mainly in the Mediterranean Basin. Unopened flower buds, called capers are used in the Mediterranean cuisine as flavoring for meat, vegetable and other foods. Several studies evaluated bioactive component and antioxidant activity of Capparis spinosa, increasing the market demand and the economic importance of capers.The aim of this work was to evaluate the contents of bioactive compounds in floral buds fermented in salt of C. spinosa collected from different areas of Pantelleria Island (Italy), testing the effect on healthy function as total antioxidant compounds. Hydrophilic extracts of C. spinosa from Pantelleria Island were char…

Toxicokinetics, toxicity and lethal body residues of two chlorophenols in the oligochaete worm, Lumbriculus variegatus, in different sediments

2003

Bioavailability, toxicokinetics and toxicity (LC(50)) of water- and sediment-associated 2,4,5-trichlorophenol (2,4,5-TCP) and pentachlorophenol (PCP) were measured in Lumbriculus variegatus Müller in a set of experiments. The critical body residue approach was applied by measuring also the lethal body residues (LBR(50)). Freshwater and three different sediments with various sediment organic carbon (SOC) concentrations were used as exposure media. SOC decreased the bioavailability of both chlorophenols, and the uptake rates decreased by 81% and 91% for 2,4,5-TCP and PCP, respectively, in the sediment with a SOC of 6.9% compared to those in sediment with a SOC of 0.5%. SOC appeared to be an i…