Search results for "ether"
showing 10 items of 986 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.
Isobaric Vapor−Liquid Equilibrium in the Systems 2,3-Dimethylpentane + Methyl 1,1-Dimethylethyl Ether, + Diisopropyl Ether and + Methyl 1,1-Dimethylp…
1999
New, consistent vapor−liquid equilibrium data for the binary systems 2,3-dimethylpentane + methyl 1,1-dimethylethyl ether, + diisopropyl ether, and + methyl 1,1-dimethylpropyl ether are reported at 101.3 kPa. The measured systems deviate slightly from ideal behavior, and only the system methyl 1,1-dimethylpropyl ether + 2,3-dimethylpentane presents an azeotrope. The activity coefficients for the solutions were correlated with their compositions by the Wilson, UNIQUAC, and NRTL models. Wisniak−Tamir equations were used to correlate the boiling points of the solutions with their compositions.
Histaminanaloge, 28. Mitt. 2-Aryloxyalkyl- und 2-Aminoalkylhistamine
1987
Als Histaminderivate mit H1-affinitatsvermittelnden Strukturelementen in 2-Stellung des Imidazolrings wurden 2-Aryloxyalkyl- und 2-Aminoalkylhistamine sowie das racemische 2-(1-Phenylethyl)histamin dargestellt und auf Histamin-H1-agonistische Aktivitat untersucht. Histamine Analogues, XXVIII: 2-(Aryloxyalkyl)- and 2-(Aminoalkyl)histamines As histamine derivatives with structures at position 2 of the imidazole ring, which mediate H1-receptor affinity, 2-(aryloxyalkyl)- and 2-(aminoalkyl)histamines as well as racemic 2-(1-phenylethyl)histamine were prepared and tested for histamine H1-agonistic activity.
Imidazolsynthesen, 10. Mitt. Zur selektiven Synthese N-substituierter Imidazol-4-äthanole
1977
Die Synthese N-substituierter Methoxyathylimidazole 5, 6 aus Aldehyden 1, 1-Hydroxy-4-methoxy-2-butanon (2), primaren Aminen 3 und Ammoniak (4) nach Weidenhagen liefert Gemische, in denen im GC die 1,4-Isomere 5 in der Regel deutlich uberwiegen. Aus diesen lassen sich durch Atherspaltung mit HJ die N-substituierten Imidazol-4-athanole 8 erhalten. Selective Synthesis of N-Substituted Imidazole-4-ethanols The synthesis of N-substituted methoxyethylimidazoles 5, 6 from aldehydes 1, 1-hydroxy-4-methoxy-2-butanone (2), primary amines 3, and ammonia (4), using the Weidenhagen cyclisation, yields mixtures in which, according to gc analysis, the 1,4-isomers 5 prevail. Ether cleavage with HI gives t…
Field desorption mass spectrometric characterization of thiol conjugates related to the oxidative metabolism of the anticancer drug 4′-(9-acridinylam…
1983
Conjugation products with glutathione (GSH) and other endogenous thiol derivatives related to the oxidative metabolism of the anticancer drug, 4′-(9-acridinlyamino) methanesulfon-m-anisidide (m-AMSA) were synthesized and characterized by field desorption mass spectrometry. The primary microsomal oxidation product of m-AMSA, m-AQDI, was prepared by MnO2 oxidation of the parent drug and reacted with equimolar GSH, cysteine, N-acetylcysteine and N-acetylcysteine methyl ester to form m-AMSA-(5′)-thiol conjugates linkedat the aniline ring, as major products. Field desorption mass spectra of the conjugates provided abundant [MH]plus; ions, and characteristic fragment ions by cleavage at the thioe…
Identification of conjugation and cleavage products in the thiolytic metabolism of the anticancer drug 4'-(9-acridinylamino)methanesulfon-m-anisidide.
1981
Conjugation and cleavage products in the thiolytic metabolism of the anticancer drug 4′ -(9-acridinyl amino)methanesulfon-m-anisidide were identified primarily by high-pressure liquid chromatography in combination with field desorption mass spectrometry. The spontaneous metabolic pathway of the drug, as related to its susceptibility to nucleophilic attack by endogenous thiols at the 9-carbon atom of the acridine moiety, has been studied. Among the metabolite fraction of 4′-(9-acridinylamino)methanesulfon-m-anisidide excreted in rat bile after administration of a therapeutic dose, a conjugate was identified as the 9-acridinyl thioether of glutathione. This conjugation product and the corresp…
Analytical capabilities of high performance liquid chromatography – Atmospheric pressure photoionization – Orbitrap mass spectrometry (HPLC-APPI-Orbi…
2015
A new analytical method was established and validated for the analysis of 27 brominated flame retardants (BFRs), including so called "emerging" and "novel" BFRs (EBFRs and NBFRs) in fish samples. High performance liquid chromatography (HPLC) coupled to Orbitrap mass spectrometry (Orbitrap-MS) employing atmospheric pressure photoionization (APPI) interface operated in negative mode was used for the identification/quantitation of contaminants. HPLC-Orbitrap-MS analysis provided a fast separation of selected analytes within 14 min, thus demonstrating a high throughput processing of samples. The developed methodology was tested by intralaboratory validation in terms of recovery, repeatability, …
In-tube solid-phase microextraction-capillary liquid chromatography as a solution for the screening analysis of organophosphorus pesticides in untrea…
2006
This paper describes a method for the selective screening of organophosphorus pesticides in water. In-tube solid-phase microextraction (SPME) in an open capillary column coupled to capillary liquid chromatography (LC) with UV detection has been used to effect preconcentration, separation and detection of the analytes in the same assembly. For in-tube SPME two capillary columns of the same length and different internal diameters and coating thicknesses have been tested and compared, a 30 cm x 0.25 mm I.D., 0.25 micro m thickness coating column, and a 30 cm x 0.1 mm I.D., 0.1 micro m of coating thickness column. In both columns the coating was 95% dimethylpolysiloxane (PDMS)-5% diphenylpolysi…
Evaluation of analytical performance of gas chromatography coupled with atmospheric pressure chemical ionization Fourier transform ion cyclotron reso…
2019
Abstract A new analytical method was established and validated for the analysis of eighteen halogenated flame retardants (HFRs)in food products. Gas chromatography (GC) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) employing atmospheric pressure chemical ionization (APCI) was used for the identification and quantitation of contaminants. Intra-laboratory validation of the method was performed with respect to recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ), and trueness was verified where possible by analysis of reference materials (RMs). The validation results indicated recoveries of ana…
Multi-analyte method for the analysis of legacy and alternative brominated and chlorinated flame retardants in food products of animal origin using g…
2019
Abstract An analytical method was developed and validated for the analysis of 32 halogenated flame retardants (HFRs), including 13 polybrominated diphenyl ethers (PBDEs), 9 dechlorane-related compounds (DRCs) and 10 of the so-called alternative BFRs in food samples of animal origin. Gas chromatography (GC) coupled with magnetic sector high resolution mass spectrometry (HRMS) was used for the instrumental analysis. Intralaboratory validation of the developed method was performed in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ). Where possible, trueness was verified by the analysis of reference materials (RMs). Fo…