Search results for "sulfide"
showing 10 items of 388 documents
Headspace Volatile Composition of the Flowers of Caralluma europaea N.E.Br. (Apocynaceae)
2009
The volatile constituents of the flowers of Caralluma (Apteranthes) europaea (Guss.) N.E. Br. (Apocynaceae - Asclepiadoideae) from Lampedusa Island were analyzed by headspace method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), a-terpinene (19.1%) and linalool (18.4%), whereas, among the carbonylic compounds the major constituents were heptanal (2.0%), octanoic acid (2.4%) and hexanoic acid (1.7%). It is worth to mention the presence of a nitrogen containing compound, indole (0.8%) and of a sulphur containing compound, dimethylsulphide (t). The compounds found in the flowers of C. europea…
Diorganotin Compounds Containing α‐Aminoacidato Schiff Base Ligands Derived from Functionalized 2‐Hydroxy‐5‐(aryldiazenyl)benzaldehyde. Syntheses, St…
2020
Untersuchungen über das Benzothiiren
1984
Thermolyse und Photolyse von 1,2,3-Benzothiadiazol 10c, liefern die Produkte 11c – 15c. Mit Hilfe der 13C-Markierungstechnik wird gezeigt, das dabei kein intermediares Benzothiiren 1c gebildet wird. Isotopomere Reaktionsprodukte gehen auf H-Verschiebungen zuruck. Durch elektronenziehende Estergruppen in 6-Position wird der Ringschlus zu den substituierten Benzothiirenen 1d, e zwar nicht bei der Thermolyse, wohl aber bei der photochemischen Reaktionsfuhrung ermoglicht. Zum Nachweis dient eine eingehende Untersuchung der bei Thermolyse, Photolyse und auf einem unabhangigen Weg erhaltenen Disulfide 14d, e, bzw. 14d′, e′ und 14d˝, e˝. Die vorliegenden Ergebnisse basieren auf 13C- und 1H-NMR-Mes…
Magnetic properties of MoS 2 nanotubes doped with lithium
2003
DC magnetization measurements of lithium-doped molybdenum sulfide nanotubes (LixMoS2, 2.2 10 kOe, the nonlinear part in H<5 kOe with saturation at approximately 10 kOe can be observed. This suggests a formation of ferromagnetic clusters even at room temperature. No magnetic phase transition between 2 and 300 K has been detected.
Herstellung und 13 C‐NMR‐Spektroskopie isomerer 1,4‐Heterophosphorinanium‐Salze
1978
Die quartaren Diallylphosphonium-Salze 1–8 werden mit Natronlauge, Natriumhyrogensulfid. Ammoniak oder prim. Aminen zu den 1,4-Oxa- (9–14), 1,4-Thia- (15–21) und 1,4-Azaphosphorinanium-Salzen (22–36) umgesetzt. Die Konformation bzw. Konfiguration der in den meisten Fallen als Isomerengemische anfallenden Salze 9–36 wird 1H- bzw. 13C-NMR-spektroskopisch untersucht. Eine Abhangigkeit von der geometrischen Anordnung sowohl der 4JPH- als auch der vicinalen3JPC-Kopplungskonstanten konnte bei diesen nicht gespannten 1,4-Diheterocylohexanen festgestellt werden. Synthesis and 13C NMR Spectra of Isomeric 1,4-Heterophosphorinanium Salts The phosphonium salts 1–8 react with aqueous sodium hydroxide, s…
Herstellung von 1,5‐Cyclooctadiin und 1,3,5,7‐Cyclooctatetraen aus 1,5‐Cyclooctadien
1994
Preparation of 1,5-Cyclooctadiyne and 1,3,5,7-Cyclooctatetraene from 1,5-Cyclooctadiene Bromination of 1,5-cyclooctadiene (1) and stepwise dehydro-bromination first with KOtBu and then with KOtBu/18-crown-6 yields 1,5-cyclooctadiyne (5). A prolonged interaction of the base causes a complete transformation to cyclooc-tatetraene (6). Diyne 5 and even more the intermediate enyne 4 are highly reactive dienophiles. The cycloadducts 10–14 formed with 1,3-cyclohexadiene, carbon disulfide, and tetraphenylcyclopentadienone were isolated and characterized. Treatment of 5 with titanium tetrachloride induces a vigorous polymerization.
ChemInform Abstract: Comprehensive Uranium Thiophosphate Chemistry: Framework Compounds Based on Pseudotetrahedrally Coordinated Central Metal Atoms.
2014
The new ternary compounds UP2S6 (I), UP2S7 (II), U(P2S6)2 (III), and U3(PS4)4 (IV) are prepared from polysulfide fluxes (evacuated quartz tube, 1.
Effects of four carbamate compounds on antioxidant parameters
2009
Abstract The effect of four carbamates, aldicarb and its metabolites (aldicarb sulfone and aldicarb sulfoxide) and propoxur on glutathione content and the activity of the enzymes involved in the sulfur-redox cycle in the mammalian cellular model CHO-K1 cells after 24-h exposure were determined. Carbamate exposure resulted in a depletion of intracellular reduced glutathione (GSH) content, no change was observed in oxidized glutathione (GSSG) and a decrease in GSH/GSSG ratio was detected. After carbamates exposition a GSH/GSSG decreases in ranged from 12.44% to 21.35% of control was observed. Depletion of GSH levels was accompanied by the induction of glutathione reductase (GR) after 24 h exp…
Highly Efficient Removal of Neonicotinoid Insecticides by Thioether-Based (Multivariate) Metal–Organic Frameworks
2021
Circumventing the impact of agrochemicals on aquatic environments has become a necessity for health and ecological reasons. Herein, we report the use of a family of five eco-friendly water-stable isoreticular metal-organic frameworks (MOFs), prepared from amino acids, as adsorbents for the removal of neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid) from water. Among them, the three MOFs containing thioether-based residues show remarkable removal efficiency. In particular, the novel multivariate MOF {SrIICuII6[(S,S)-methox]1.5[(S,S)-Mecysmox]1.50(OH)2(H2O)}·36H2O (5), featuring narrow functional channels decorated with both -CH2SCH3 and -CH2…
Cytotoxic effect of As(III) in Caco-2 cells and evaluation of its human intestinal permeability.
2005
Inorganic arsenic has been classified as a carcinogen for humans (Group I). However, its transit across the human intestinal epithelium has not been characterized. Using Caco-2 cells, the thiol-redox balance and apparent permeability coefficients (P(app)) for As(III) in the apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction were evaluated. After As(III) exposure, GSH-induced synthesis was observed, increasing the GSH/GSSG ratio by elevating the As(III) concentration. The AP-BL permeabilities decreased as the As(III) concentrations increased, indicating the existence of a mediated transport mechanism. The (BL-AP)/(AP-BL) permeability ratios were higher than unity, sugg…