Search results for "Petroleum ether"
showing 10 items of 11 documents
Cytotoxic Activity and Composition of Petroleum Ether Extract from Magydaris tomentosa (Desf.) W. D. J. Koch (Apiaceae)
2015
The petroleum ether extract of Magydaris tomentosa flowers (Desf.) W. D. J. Koch has been analyzed by GC-MS. It is mainly constituted by furanocoumarins such as xanthotoxin, xanthotoxol, isopimpinellin, and bergaptene. Other coumarins such as 7-methoxy-8-(2-formyl-2-methylpropyl) coumarin and osthole also occurred. The antiproliferative activity of Magydaris tomentosa flower extract has been evaluated in vitro on murine monocye/macrophages (J774A.1), human melanoma (A375) and human breast cancer (MCF-7) tumor cell lines, showing a major activity against the latter.
Liquid chromatography-Fourier transform infrared spectrometric determination of cholesterol in animal greases
1997
Abstract Stearic acid, cholesterol and cholesteryl palmitate have been separated in less than 14 min by liquid chromatography on a column (3.9 mm i.d.×150 mm) of Nova-Pack C 18 (5 μm) using chloroform–acetonitrile (45 : 55) as mobile phase pumped at 0.5 ml min −1 ; Fourier transform infrared (FTIR) spectrometry was employed for both, general detection at 2868 or 2855 cm −1 and selective detection at 3285 cm −1 for stearic acid and 3526 cm −1 for cholesterol. In all cases a baseline established at 3900 cm −1 , 9-point smoothing and chromatographic peak height measurements were used. The method has been validated by application to the determination of cholesterol in animal greases and fish oi…
Separation and identification of piperine and chavicine in black pepper by TLC and GC-MS
2006
Conventional extraction of piperine and its derivatives by stirring the black pepper powder with solvents (ethyl alcohol, chloroform, petroleum ether, diethyl ether, etc.) for 16 to 24 h, or in a Soxhlet device for 16 h, can be replaced by extraction with supercritical fluids (CO 2 , CO + ethanol mixtures) [5, 6], or can be aided by use of microwave irradiation [7]. Separation and identification of the compounds present in pepper (essential oils, alkaloids, etc.) has been achieved by gas chromatography combined with mass spectrometry [8] and by thin-layer chromatography [9, 10]. C. Marutoiu, M.I. Moise, Lucian Blaga University of Sibiu, Faculty of Agricultural Sciences, Food Industry, and E…
Microwave-assisted saponification of animal greases for cholesterol determination
1998
Abstract An alternative method for the hydrolysis of cholesterol esters in animal grease samples has been developed. The method consists of the microwave-assisted treatment of 4 g of animal fat or oil with 40 ml of an ethanolic KOH solution inside a 115 ml closed reactor in which samples were irradiated for 2.5 min at 50% power level of an exit power of 700 W. After extraction with petroleum ether and dissolution of the unsaponifiables in toluene, total cholesterol was determined spectrophotometrically by using p-anisidine as a test reagent of the enzymatic reaction of cholesterol through a bienzymic reactor in which cholesterol oxidase and horseradish peroxidase were noncovalently immobili…
Contributions to the analysis of organic xenobiotics in fish
1995
For the residue-analysis of fish samples, a method has been developed to separate the medium polar triazines and acetamides together with lipophilic xenobiotics (organochlorine pesticides, PCBs and octachlorostyrene) from fish tissue. The detection limits of the analytes are mostly within the ppt-range (ng/kg fillet) and vary between 40 and 1050 ng/kg fillet of fish. Their recoveries range from 75 to 108%, spiked at 1.5 μg/kg. The substances are extracted with a mixture of petroleum ether/ethylacetate (2:1) using a soxhlet apparatus. Subsequently, the lipids in the sample extracts are reduced to 0.4% by gel chromatography. A 5 g silica gel clean-up separates the analytes according to their …
Phytochemical analysis ofAchillea ligusticaAll. from Lipari Island (Aeolian Islands)
2016
A complete chemical investigation of Achillea ligustica All. growing at Lipari (Aeolian Island, Sicily) has been carried out. Seventeen metabolites have been isolated and characterised from dichloromethane and methanol extracts of flowers and aerial parts, and GC/MS analyses of petroleum ether extracts was carried out, revealing a composition in sesquiterpenoids similar to those reported for populations from Greece, Sicily and Algeria, showing the presence of (3RS,6RS)-2,6-dimethyl-1,7-octadiene-3,6-diol (1), 2,6-dimethyl-octa-3(E),7-diene-2,6-diol (2), iso-seco-tanapartholide (3) from DCM fraction. In addition from the methanolic extract of the aerial parts, peculiar flavonoid glucuronides…
Continuous polymer fractionation of poly(methyl vinyl ether) and a new Kuhn-Mark-Houwink relation
1995
Continuous polymer fractionation (CPF) — a new large-scale method — was applied to the technical poly(methyl vinyl ether) (PVME) using toluence as solvent and petroleum ether as non-solvent. Two different devices served as fractionation apparatus, namely a column packed with glass beads and a set of mixer-settler extractors. Advantages and draw-backs of these devices are discussed. The experiments yielded numerous PVME fractions, varying in molar mass from 22 to 87 kg/mol and in molecular non-uniformity U = (M¯w/Mn) – 1 from 0,25 to 0,41 according to gel-permeation chromatography as compared with ca. U = 1,30 for the starting material. The following Kuhn-Mark-Houwink relation was establishe…
Influencia del procesado industrial sobre las características químico-físicas y contenido en lípidos y antioxidantes del salvado de arroz
2009
Se investigaron las características químico-físicas de los salvados de arroz en distintos momentos de su procesado industrial, incluyendo materia prima (salvados de arroz blanco y vaporizado), salvado peletizado y salvado desgrasado. Se determinó la humedad, la acidez y el índice de peróxidos. Utilizando extractos en éter de petróleo y cromatografía de gases, se estableció el contenido lipídico total y los perfiles de los ácidos grasos. Mediante HPLC se determinaron los tocoferoles y el γ-orizanol. El salvado de arroz vaporizado mostró la mayor concentración de lípidos y la menor acidez, lo que indica que el vaporizado es el proceso más eficaz para estabilizar el salvado. Los ácidos oleico,…
Chemical composition of volatile and fixed oils from of Salvia argentea L. (Lamiaceae) growing wild in Sicily.
2015
The chemical compositions of the essential oil and of the non-polar extracts (petroleum ether, dichloromethane) of the aerial parts (flowers, leaves and stems) of Salvia argentea L. were determined by GC-FID and gas chromatographyâmass spectrometry analysis. 14-Hydroxy-α-humulene (40.1%) was recognised as the main constituents of the essential oil of S. argentea, together with 1,3,8-p-menthatriene (12.1%), globulol (7.4%) and β-sesquiphellandrene (5.8%). Tritriacontane (9.9% and 14.1%), heptacosane (8.4% and 10.5%), hentriacontane (8.3% and 10.9%), tetradecanal (8.4% and 10.2%) and methyldotriacontane (7.9% and 7.6%) were recognised as the main constituents of the extracts in petroleum …
An Efficient Synthesis of Rubin’s Aldehyde and its Precursor 1,3,5-Tribromo-2,4,6-tris(dichloromethyl)benzene
2011
2,4,6-Tribromobenzene-1,3,5-tricarboxaldehyde (4) can be efficiently prepared in two reaction steps from 1,3,5-tribromobenzene. The intermediate 1,3,5-tribromo-2,4,6-tris(dichloromethyl)benzene (3) crystallizes from petroleum ether in its C3h structure. However, in CDCl3 solution it exists at room temperature in two isomeric forms: 3a (C3h) and 3b (Cs) (1:1.15).The intramolecular Br・・・Cldistances are much smaller than the sum of the van der Waals radii. Therefore, the exocyclic C-C bonds show a hindered rotation.