Search results for "Sulfur Compounds"
showing 10 items of 30 documents
Diode laser spectroscopy of the nu(8) band of the SF(5)Cl molecule.
2003
Abstract Diode laser spectra of SF 5 Cl have been recorded in the ν 8 band region at a temperature of ca. 240 K, a pressure of 0.25 mbar and an instrumental bandwidth of ca. 0.001 cm −1 . Four regions have been studied: a first one in the P -branch (906.849–907.687 cm −1 ), a second one in the Q -branch (910.407–910.944 cm −1 ), and two other ones in the R -branch (913.957–914.556 and 917.853–918.705 cm −1 ). The whole ν 1 / ν 8 dyad of SF 5 35 Cl has been previously recorded in the group of Professor H. Burger in Wuppertal, thanks to a Fourier transform infrared spectrometer [J. Mol. Spectrosc. 208 (2001) 169]. These data have thus been combined with our diode laser ones in the aim of refi…
Polythiophenes as markers of asphalt and archaeological tar pitch aging. Characterization using solid-state electrochemistry
2018
The voltammetry of immobilized microparticles (VIMP) was used to characterize organosulfur components from ovens found at the Spanish archaeological sites of Cueva de Nerja (ca. 35,000cal BC), la Illeta dels Banyets (4th century BCE) and Gestalgar (12th–13th CE), and asphalt probes subjected to PAV and SUNTEST aging protocols. The voltammetric responses of the archaeological samples and the asphalt probes after photodegradation were quite similar, indicating the presence of polythiophene components which could act as age/degradation markers. Keywords: Voltammetry, Archaeology, Asphalt, Tar pitch, Organosulfur compounds
Effect of onion consumption by rats on hepatic drug-metabolizing enzymes
2001
Fruits and vegetables or their natural constituents which increase detoxication enzymes and/or reduce activating enzymes are considered as good candidates to prevent chemically-induced carcinogenesis. In this study, rats were fed a diet supplemented with 20% onion powder for 9 days. Several cytochrome P450 (CYP)s enzymes (CYP 1A, 2B, 2E1, 3A), which are involved in carcinogen activation, were determined by measuring their enzyme activities using specific substrates. In addition, phase II enzymes activities such as UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST), involved in detoxication of carcinogens, were measured. Protein levels of CYPs and GST A1/A2, A3/A5, Ml, M2 …
Sensitivity to allyl isothiocyanate, dimethyl trisulfide, sinigrin, and cooked cauliflower consuption
2006
International audience; The consumption of cauliflower consumers has been related to the olfactory and gustatory sensitivities to potentially objectionable flavor compounds in this vegetable. Based on the ascending concentration series method of limits, a first experiment was designed to develop rapid tests dedicated to estimate individuals' olfactory thresholds for allyl isothiocyanate (AITC) and dimethyl trisulfide (DMTS) and gustatory thresholds for sinigrin (SIN). The best compromise between rapidity and reliability was obtained with two replications of a four-alternative forced choice (AFC) at six ascending concentrations (6×2×4-AFC) for both AITC and DMTS, and with a 6×1×4-AFC for SIN…
Stability and extraction of bioactive sulfur compounds from Allium genus processed by traditional and innovative technologies
2017
Abstract Since ancient times, species from the Allium genus have been used in both culinary and medicinal applications. The health promoting properties, with well documented “evidence-based” studies, were attributed to the genus’ high content of bioactive organosulfur compounds. For these reasons, the organosulfur compounds have attracted interest in both food and pharmaceutical industries to be used as additives or supplements. Therefore, improvement in the extraction and stability during processing and storage of these molecules is crucial. The presented review documents the effects of traditional and innovative processing techniques on the extraction and stability of organosulfur compoun…
Sulfites and the Wine Metabolome
2017
International audience; In a context of societal concern about food preservation, the reduction of sulfite input plays a major role in the wine industry. To improve the understanding of the chemistry involved in the SO2 protection, a series of bottle aged Chardonnay wines made from the same must, but with different concentrations of SO2 added at pressing were analyzed by ultrahigh resolution mass spectrometry (FT-ICR-MS) and excitation emission matrix fluorescence (EEMF).Metabolic fingerprints from FT-ICR-MS data could discriminate wines according to the added concentration to the must but they also revealed chemistry-related differences according to the type of stopper, providing a wine me…
Solid state electrochemical behavior of organosulfur compounds
2017
Abstract The solid-sate electrochemistry of organosulfur compounds existing in petroleum and its derived matrices is described using the voltammetry of immobilized microparticles methodology. Cyclic and square wave voltammogrammetric responses of sulfur compounds responsible of aging of asphalt pavements, namely, thiophenes, disulfides, sulfides, sulfoxides and sulfones were determined at compound-modified graphite electrodes in contact with 0.10 M H2SO4. The electrochemical oxidation/reduction products were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy with energy dispersion x-ray detection (SEM-EDX) couple…
Environmentally relevant precursors of carbonyl sulfide in aquatic systems
1997
Seawater solutions of environmentally relevant organosulfur compounds, commercial humic acid (HA), and natural dissolved organic matter (DOM) were incubated with and without UV light in order to determine the carbonyl sulfide (COS) producing capabilities of these compounds. COS dark- and photo-production rate constants were determined for dilute solutions of the organosulfur compounds (μmol l−1) and HA/DOM (mg l−1). Dissolved COS was determined using a purge and cryogenic trap method followed by GC/FPD detection. COS was produced in considerable amounts both non-photochemically and photochemically from the reduced form of free acid of glutathione (GSH) and photochemically from cysteine (CYS…
Reversible Solvent‐Exchange‐Driven Transformations in Multifunctional Coordination Polymers Based on Copper‐Containing Organosulfur Ligands
2014
The preparation by simple direct synthesis of a series of coordination polymers based on copper with chloride or bromide and dipyrimidinedisulfide is reported. The structural characterisations of these compounds reveal a rich structural variety as a result of the number of coordination modes available to the organosulfur ligand, in combination with the bridging capabilities of the halides. Interestingly, some of the polymers displayed fully reversible solvent exchange/removal crystal-to-crystal 2D to 0D and 2D to 2D transformations. These materials show multifunctional electronic properties. Thus, some of them are semiconductors and present weak antiferromagnetic interactions, and the CuI/C…
An overview of organosulfur compounds from Allium spp.: From processing and preservation to evaluation of their bioavailability, antimicrobial, and a…
2019
The use of Allium species and their extracts has been known since immemorial times due to their health beneficial properties. It is known that functional properties of Allium genus come from the high content of bioactive compounds. The biological activity of Allium extracts will be conditioned by the type of Allium variety, agricultural conditions, and specific extraction process used since all these factors affect the content and the profile of bioactive compounds. Innovative extraction techniques in comparison to conventional processes could be considered as a promising tool to recover bioactive compounds from Allium spp. with antimicrobial and anti-inflammatory properties. Trying to fill…