Search results for "Cyclohexene"
showing 10 items of 47 documents
Genotoxicity of citrus wastewater in prokaryotic and eukaryotic cells and efficiency of heterogeneous photocatalysis by TiO(2).
2012
Abstract The presence of (±)α-pinene, (+)β-pinene, (+)3-carene, and R-(+)limonene terpenes in wastewater of a citrus transformation factory was detected and analyzed, in a previous study, by using Solid Phase Micro-extraction (SPME) followed by GC analyses. Purpose of that research was to compare the genotoxic responses of mixtures of terpenes with the genotoxicity of the individual compounds, and the biological effects of actual wastewater. Genotoxicity was evaluated in the Salmonella reversion assay (Ames test) and in V79 cells by Comet assay. Ames tests indicated that the four single terpenes did not induce an increase of revertants frequency. On the contrary, the mixtures of terpenes ca…
Catalytic Oxidation of Alkanes and Alkenes by H 2 O 2 with a μ‐Oxido Diiron(III) Complex as Catalyst/Catalyst Precursor
2015
A new mu-oxo diiron(III) complex of the lithium salt of the pyridine-based unsymmetrical ligand 3-[(3-{[bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzyl)(pyridin2-ylmethyl)amino] propanoate (LiDPCPMPP), [Fe-2(mu-O)(LiDPCPMPP)(2)](ClO4)(2), has been synthesized and characterized. The ability of the complex to catalyze oxidation of several alkanes and alkenes has been investigated by using CH3COOH/H2O2 (1:1) as an oxidative system. Moderate activity in cyclohexane oxidation (TOF = 33 h(-1)) and good activity in cyclohexene oxidation (TOF = 72 h(-1)) were detected. Partial retention of configuration (RC = 53%) in cis- and trans-1,2-dimethylcyclohexane oxidation, moderate 3 degrees…
(-)-(3a ' S,4 ' S,9b ' S,1R,2S,5R)-4 '-ethyl-3a ',4 ',5 ',7 ',8 ',9b '-hexahydro-2-isopropyl-5-methyl-2 '-phenylspiro[cyclo-hexane-1,7 '-dioxino[3,2-…
2005
The title compound, C27H33NO5, obtained from diethyl ether, crystallizes in space group P2(1) with four molecules in the asymmetric unit. The dioxinone and imide rings are almost planar, whereas the cyclohexane and cyclohexene rings form distorted conformations. The crystal structure confirms an earlier proposal about the stereoselectivity of Diels - Alder reactions to spirocyclic chiral 1,3- dienes.
Highly Enantioselective Kinetic Resolution of Michael Adducts through N-Heterocyclic Carbene Catalysis: An Efficient Asymmetric Route to Cyclohexenes
2018
Ahighly efficient strategy for the kinetic resolu-tion of Michael adductswas realized using achiral N-het-erocyclic carbene catalyst.The kinetic resolution providesanew convenientroute to single diastereomers of cyclo-hexenes and Michael adducts in good yields with highenantiomeric excesses (up to 99 % ee with aselectivityfactor of up to 458). This “two flies with one swat” con-cept allows the synthesis of these two synthetically valua-ble compound classes at the same time by asingle trans-formation. peerReviewed
Polyoxygenated Cyclohexenes and Other Constituents of Cleistochlamys kirkii Leaves.
2016
Thirteen new metabolites, including the polyoxygenated cyclohexene derivatives cleistodiendiol (1), cleistodienol B (3), cleistenechlorohydrins A (4) and B (5), cleistenediols A-F (6-11), cleistenonal (12), and the butenolide cleistanolate (13), 2,5-dihydroxybenzyl benzoate (cleistophenolide, 14), and eight known compounds (2, 15-21) were isolated from a MeOH extract of the leaves of Cleistochlamys kirkii. The purified metabolites were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of compounds 1, 17, and 19 were established by single-crystal X-ray diffraction. The configuration of the exocyclic double bond of compound 2 was revised base…
Fabrication of Porous Hydrogenation Catalysts by a Selective Laser Sintering 3D Printing Technique
2019
Open in a separate window Three-dimensional selective laser sintering printing was utilized to produce porous, solid objects, in which the catalytically active component, Pd/SiO2, is attached to an easily printable supporting polypropylene framework. Physical properties of the printed objects, such as porosity, were controlled by varying the printing parameters. Structural characterization of the objects was performed by helium ion microscopy, scanning electron microscopy, and X-ray tomography, and the catalytic performance of the objects was tested in the hydrogenation of styrene, cyclohexene, and phenylacetylene. The results show that the selective laser sintering process provides an alte…
Abnormal mitotic spindle assembly and cytokinesis induced by D-Limonene in cultured mammalian cells
2013
D-Limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. With the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to D-Limonene and elucidate its, as yet unknown, mechanism of action. We reported here that D-Limonene is toxic in V79 Chinese hamster cells in a dose-dependent manner. Moreover, to determine the cellular target of D-Limonene, we performed morphological observations and immunocytochemical analysis and we showed that this drug has a direct effect on dividing cells preventing assembly of mito…
Identification of highly effective antitrypanosomal compounds in essential oils from the Apiaceae family
2018
The Apiaceae family encompasses aromatic plants of economic importance employed in foodstuffs, beverages, perfumery, pharmaceuticals and cosmetics. Apiaceae are rich sources of essential oils because of the wealth of secretory structures (ducts and vittae) they are endowed with. The Apiaceae essential oils are available on an industrial level because of the wide cultivation and disposability of the bulky material from which they are extracted as well as their relatively cheap price. In the fight against protozoal infections, essential oils may represent new therapeutic options. In the present work, we focused on a panel of nine Apiaceae species (Siler montamon, Sison amomum, Echinophora spi…
A Synthetic Model for the [4+2] Cycloaddition in the Biosynthesis of the Brevianamides, Paraherquamides, and Related Compounds
2000
Abstract The reactivity of model systems for the proposed [4+2] cycloaddition in the biosynthesis of the brevianamides, paraherquamides, and marcfortines is explored. The model for the intermolecular reaction reveals that the cycloaddition takes place under mild conditions only if activated, very reactive dienophiles are used. When relatively unreactive dienophiles such as cyclopentene and cyclohexene are used, harsh reaction conditions and/or a Lewis acid catalyst are necessary for the reaction. In contrast, the model for the intramolecular reaction demonstrates that the cycloaddition takes place within a few hours at room temperature, even in the absence of a Lewis acid catalyst. Conclusi…
Blocking signaling through the gp130 receptor chain by interleukin-6 and oncostatin M inhibits PC-3 cell growth and sensitizes the tumor cells to eto…
1999
BACKGROUND The mechanisms of drug resistance associated with advanced, hormone-independent prostate carcinoma are poorly understood. The human prostate carcinoma PC-3 cell line, derived from a metastatic tumor and lacking androgen receptors, represents a useful model to investigate drug resistance. METHODS The effects of oncostatin M (OM), antiinterleukin-6 (IL-6) treatment, or interference with the gp130-mediated signaling on etoposide- or cisplatin-mediated cytotoxicity were investigated. RESULTS Both endogenous and exogenous IL-6 and exogenous OM up-regulated cell growth and enhanced resistance of PC-3 tumor cells to both etoposide and cisplatin. The influence of IL-6 is controlled by tr…