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Methyl Ether (methyl + ether)
Kinds of Methyl Ether Selected AbstractsFlexible Route to Palmarumycin CP1 and CP2 and CJ-12.371 Methyl EtherEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 23 2010Karsten Krohn Abstract The total synthesis of palmarumycin CP1 (4) and CP2 (5) and racemic CJ-12.371 methyl ether (17) is described using the Diels,Alder reaction of benzoquinone 1,8-dihydroxynaphthalene acetal (10) with 1-methoxy-1,3-butadiene under neat reaction conditions. The stereochemistry of adduct 15 was confirmed by single-crystal X-ray analysis. The transformation of 15 into target products 4, 5, and 17 involved dehydrogenation, methyl ether cleavage, and reduction and oxidation steps. [source] Odoriferous Cyclic Ethers via Co-Halogenation Reaction: Facile Preparation of Nerol Oxide, Florol®, Florol® Methyl Ether, and Pityol® Methyl EtherHELVETICA CHIMICA ACTA, Issue 1 2007Pankaj Gupta Abstract A series of odoriferous cyclic ethers, including nerol oxide (1), Florol® (2), Florol methyl ether (3), and Pityol® methyl ether (4b), were prepared by a versatile synthetic protocol based on co-halogenation with 1,3-dibromo-5,5-dimethylhydantoin (=,1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione; DDH) as the key step. The methodology provides a facile access to important perfumery molecules from abundantly available monoterpene alcohols. [source] Copolymerization of Ethylene with 2,7-Octadienyl Methyl Ether in the Presence of Metallocene and Nickel Diimine CatalystsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 7 2009Mércia Fernandes Abstract In this work, copolymers of ethylene with 2,7-octadienyl methyl ether have been synthesized in the presence of three single-site catalysts. The obtained copolymers not only have a polar ether function but also a double bond in the side chains that is useful for secondary reactions. The polymers were characterized by GPC, EA, DSC, NMR, and FT-IR. The catalytic activity depends on the kind of catalysts, the concentration of the polar monomer, and the concentration of the protecting agent. Up to 7.3 wt.-% of MODE could be incorporated by the metallocene catalyst. These are in average 120 functional side groups in a polymer molecule with a molecular mass of 230,000. [source] ChemInform Abstract: The Reaction of 1-Silylcyclopropyl Anions with Dichloromethyl Methyl Ether: The Efficient Synthesis of Cyclopropyl Silyl Ketones via Cyclopropylidene Derivatives.CHEMINFORM, Issue 23 2010Toshiaki Nishizawa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: NbCl5 -Mediated Deprotection of Methoxy Methyl Ether.CHEMINFORM, Issue 44 2009J. S. Yadav Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Diphenylprolinol Methyl Ether: A Highly Enantioselective Catalyst for Michael Addition of Aldehydes to Simple Enones.CHEMINFORM, Issue 4 2006Yonggui Chi Abstract For Abstract see ChemInform Abstract in Full Text. [source] An Efficient Synthesis of Substituted meta -Halophenols and Their Methyl Ethers: Insight into the Reaction MechanismEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2010Faiz Ahmed Khan Abstract An expeditious synthetic methodology leading to substituted meta -halophenols and their corresponding methyl ether derivatives through acid-mediated fragmentation of suitably substituted dihalonorbornyl ketones has been devised. The reaction sequence consists of TBTH-mediated (TBTH is tri- n -butyltin hydride) selective bridgehead halogen reduction of easily accessible Diels,Alder adducts derived from 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene and ,-substituted vinyl acetates, with subsequent conversion into the requisite bicyclic ketones by a two-step hydrolysis/oxidation approach. An extensive mechanistic investigation based on isotope labeling and cross experiments has been carried out and plausible mechanistic pathways based on these results have been proposed. The absence of halogen atoms at the bridgehead positions steers the reaction through a novel pathway involving the incorporation of proton (or deuterium) followed by elimination of HX (or DX), so the described methodology also provides a reliable route to ortho-para dideuteratedphenolic derivatives. [source] ChemInform Abstract: 1-Decanethiol, a New Reagent for the Odorless Deprotection of Aryl Methyl Ethers.CHEMINFORM, Issue 39 2010Bhima Kale Abstract The practical method allows an essentially odorless aqueous work-up. [source] ChemInform Abstract: A Novel Synthesis of Aryl Mesylates via One-Pot Demethylation,Mesylation of Aryl Methyl Ethers Using a Mixture of Phosphorus Pentoxide in Methanesulfonic Acid.CHEMINFORM, Issue 43 2009Babak Kaboudin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Selective Platinum-Catalyzed C,F Bond Activation as a Route to Fluorinated Aryl Methyl Ethers.CHEMINFORM, Issue 37 2009Heather L. Buckley Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Lewis Acid Catalyzed Cascade Reactions of Diarylvinylidenecyclopropanes and 1,1,3-Triarylprop-2-yn-1-ols or Their Methyl Ethers.CHEMINFORM, Issue 7 2009Min Shi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Nickel-Catalyzed Cross-Coupling of Aryl Methyl Ethers with Aryl Boronic Esters.CHEMINFORM, Issue 44 2008Mamoru Tobisu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: An Efficient Method for Demethylation of Aryl Methyl Ethers.CHEMINFORM, Issue 39 2008Li Zuo Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Chelation-Controlled Selectivity in the Clay-Catalyzed Deprotection of Phenolic Methoxy Methyl Ethers.CHEMINFORM, Issue 42 2001Jay P. Deville Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Miconidin and miconidin methyl ether from Primula obconica Hance: new allergens in an old sensitizerCONTACT DERMATITIS, Issue 4 2006Evy Paulsen Several chemical and clinical observations have suggested the presence of at least one more allergen in addition to primin in Primula obconica. The aim of this study was to investigate the allergenicity of the primin precursor miconidin and the related miconidin methyl ether, both isolated from P. obconica. 12 primin-positive persons were patch tested with miconidin 0.01% petrolatum (pet.), miconidin in 96% ethanol incorporated into 0.01% pet., and miconidin methyl ether 1.0% pet. All persons were positive to miconidin 0.01% pet., with the strength of reactions very similar to those of the individual primin reactions, and remained inexplicably negative while testing with miconidin in 96% ethanol and pet., while miconidin methyl ether elicited 7 positive reactions. Although both miconidin and miconidin methyl ether may be allergenic only due to their conversion to primin in the skin, the presence of these substances nevertheless has to be taken into account when assessing the allergenicity of new P. obconica cultivars. [source] Contact allergy to isoeugenol and its derivatives: problems with allergen substitutionCONTACT DERMATITIS, Issue 5-6 2004S. Tanaka A total of 2261 (808 male, 1453 female) consecutive patients attending contact dermatitis clinics were patch tested to isoeugenol and its derivatives listed in the EU Inventory of Fragrance Ingredients. Positive reactions were found to isoeugenol in 40, transisoeugenol in 40, isoeugenyl acetate in 19, isoeugenyl benzoate in 4, isoeugenyl phenylacetate in 16, isoeugenyl methyl ether in 6 and benzyl isoeugenyl ether in 2 patients. There was a concomitant reaction to isoeugenol in 36/40 of those positive to transisoeugenol, 13/19 of those to isoeugenyl acetate, 3/4 of those to isoeugenyl benzoate and 15/16 of those to isoeugenyl phenylacetate but in none of those 6 positive to isoeugenyl methyl ether and in neither of those 2 positive to benzyl isoeugenyl ether. Concomitant contact allergy between isoeugenol and its derivatives may occur through chemical cross-reactivity or local skin metabolism of the derivatives. It is more commonly observed with the esters rather than the ethers. Isoeugenyl acetate has been proposed as an alternative to isoeugenol, but there is a high degree of concomitant reactivity with isoeugenol. [source] Achiral and chiral separations using MEKC, polyelectrolyte multilayer coatings, and mixed mode separation techniques with molecular micellesELECTROPHORESIS, Issue 6 2010Candace A. Luces Abstract Mixed mode (MM) separation using a combination of MEKC and polyelectrolyte multilayer (PEM) coatings is herein reported for the separation of achiral and chiral analytes. Many analytes are difficult to separate by MEKC and PEM coatings alone. Therefore, the implementation of a MM separation provides several advantages for overcoming the limitations of these well-established methods. In this study, it was observed that achiral separations using MEKC and PEM coatings individually resulted in partial resolution of eight very similar aryl ketones when the molecular micelle (sodium poly(N -undecanoyl- L -glycinate)) concentration was varied from 0.25 to 1.00%,w/v and the bilayer number varied from 2 to 4. However, when MM separation was introduced, baseline resolution was achieved for all eight analytes. In the case of chiral separations, temazepam, aminoglutethimide, benzoin, benzoin methyl ether, and coumachlor were separated using the three separation techniques. For chiral separations, the chiral molecular micelle, sodium poly(N -undecanoyl- L -leucylvalinate), was employed at concentrations of 0.25,1.50%,w/v for both MEKC and PEM coatings. Overall, the results revealed partial separation with MEKC and PEM coatings individually. However, MM separation enabled baseline separation of each chiral mixture. The separation of achiral and chiral compounds from different compound classes demonstrates the versatility of this MM approach. [source] Nanowires for surface enlargement of narrow-bore fused-silica tubingELECTROPHORESIS, Issue 21-22 2004Andreas Woldegiorgis Abstract A method for preparation of silica nanowires with dimensions of d = 10,100 nm, l = 5,500 nm, is described. The nanostructured material is an integral part of the inner surface of narrow bore fused-silica capillary tubing. The wire preparation method is based on a decomposition of 2-chloro-1,1,2-trifluoroethyl methyl ether at elevated temperature and pressure. The silica bulk material is rearranged via a sustained silica-hydrogen fluoride chemistry, and reaction mechanisms for this process are proposed. The method is suitable for preparing long lengths of tubing with the modified surface. It is our belief that the texture of the capillary wall with its increased surface area is useful for applications such as microreactions, catalysis, and high-resolution pressure and/or electrodriven open-tubular liquid chromatography. [source] Selection and identification of bacterial strains with methyl- tert -butyl ether, ethyl- tert -butyl ether, and tert -amyl methyl ether degrading capacitiesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Jessica Purswani Abstract Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl- tert -butyl ether (MTBE), ethyl- tert -butyl ether (ETBE), and tert -amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fD1 and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies. [source] Flexible Route to Palmarumycin CP1 and CP2 and CJ-12.371 Methyl EtherEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 23 2010Karsten Krohn Abstract The total synthesis of palmarumycin CP1 (4) and CP2 (5) and racemic CJ-12.371 methyl ether (17) is described using the Diels,Alder reaction of benzoquinone 1,8-dihydroxynaphthalene acetal (10) with 1-methoxy-1,3-butadiene under neat reaction conditions. The stereochemistry of adduct 15 was confirmed by single-crystal X-ray analysis. The transformation of 15 into target products 4, 5, and 17 involved dehydrogenation, methyl ether cleavage, and reduction and oxidation steps. [source] Chemical composition of essential oil from the seeds of Nigella arvensis L. and assessment of its actimicrobial activityFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2006J. Havlik Abstract The essential oil from Nigella arvensis L. was obtained by hydrodistillation, yielding 0.42% of oil on dry weight basis. The GC and GC-MS analyses showed the presence of 69 components, predominantly monoterpenes. The major constituents were carvacrol methyl ether (26.4%), , -pinene (21.4%), n -undecane (13.2%), and , -pinene (5.7%). The oil did not exhibit antimicrobial activity when tested by microdilution method. Copyright © 2006 John Wiley & Sons, Ltd. [source] The essential oil composition of Eupatorium cannabinum L. from IranFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2006Katayoun Morteza-Semnani Abstract The composition of the essential oil obtained from the dried aerial parts of Eupatorium cannabinum L. (Compositae) was analyzed by GC and GC-MS. Forty-seven components were identified in this oil. The major constituents of the essential oil were , -terpinene (17.8%), germacrene D (9.1%) and thymol methyl ether (5.2%). The essential oil of the aerial parts of E. cannabinum is rich in sesquiterpenoids. Copyright © 2006 John Wiley & Sons, Ltd. [source] Used Motor Oil as a Source of MTBE, TAME, and BTEX to Ground WaterGROUND WATER MONITORING & REMEDIATION, Issue 4 2002Ronald J. Baker Methyl tert-butyl ether (MTBE), the widely used gasoline oxygenate, has been identified as a common ground water contaminant, and BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) have long been associated with gasoline spills. Because not all instances of ground water contamination by MTBE and BTEX can be attributed to spills or leaking storage tanks, other potential sources need to be considered. In this study, used motor oil was investigated as a potential source of these contaminants. MTBE in oil was measured directly by methanol extraction and gas chromatography using a flame ionization detector (GC/FID). Water was equilibrated with oil samples and analyzed for MTBE, BTEX, and the oxygenate tert-amyl methyl ether (TAME) by purge- and-trap concentration followed by GC/FID analysis. Raoult's law was used to calculate oil-phase concentrations of MTBE, BTEX, and TAME from aqueous-phase concentrations. MTBE, TAME, and BTEX were not detected in any of five new motor oil samples, whereas these compounds were found at significant concentrations in all six samples of the used motor oil tested for MTBE and all four samples tested for TAME and BTEX. MTBE concentrations in used motor oil were on the order of 100 mg/L. TAME concentrations ranged from 2.2 to 87 mg/L. Concentrations of benzene were 29 to 66 mg/L, but those of other BTEX compounds were higher, typically 500 to 2000 mg/L. [source] Two New Endiandric Acid Analogs, a New Benzopyran, and a New Benzenoid from the Root of Beilschmiedia erythrophloiaHELVETICA CHIMICA ACTA, Issue 11 2008Ping-Shin Yang Abstract Phytochemical investigation of the root of Beilschmiedia erythrophloia led to the isolation and structural elucidation of two new endiandric acid analogs, endiandric acids I and J (1 and 2, resp.), a new benzopyran, dehydrooligandrol methyl ether (3), and a new benzenoid, farnesylol (4), together with six known compounds. Their structures were established on the basis of extensive 1D- and 2D-NMR analyses in combination with HR-MS experiments. [source] Odoriferous Cyclic Ethers via Co-Halogenation Reaction: Facile Preparation of Nerol Oxide, Florol®, Florol® Methyl Ether, and Pityol® Methyl EtherHELVETICA CHIMICA ACTA, Issue 1 2007Pankaj Gupta Abstract A series of odoriferous cyclic ethers, including nerol oxide (1), Florol® (2), Florol methyl ether (3), and Pityol® methyl ether (4b), were prepared by a versatile synthetic protocol based on co-halogenation with 1,3-dibromo-5,5-dimethylhydantoin (=,1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione; DDH) as the key step. The methodology provides a facile access to important perfumery molecules from abundantly available monoterpene alcohols. [source] Benzofuranyl-pyran-2-ones, -pyridazines, and -pyridones from naturally occurring furochromones (visnagin and khellin)HETEROATOM CHEMISTRY, Issue 1 2004Eman M. Keshk The novel and versatile enaminones 2a,b were synthesized by treatment of visnaginone methyl ether 1a or khellinone methyl ether 1b with N,N -dimethylformamide dimethylacetal. They were reacted with hippuric acid or N -acetylglycine to yield benzofuran-5-yl-2H-pyran-2-ones 3a,d. The reaction of 2a,b with cyanoacetamide and malononitrile dimer in sodium ethoxide gave benzofuran-5-yl-pyridones 4a,b and [benzofuran-5-yl-1H-pyridine-2-ylidene] malononitrile 5a, respectively. Refluxing 2a,b with hydrazine hydrate or with hydroxyla- mine afforded benzofuran-5-yl-1H-pyrazoles 6a,b and benzofuran-5-yl-isoxazoles 7a,b, respectively. Moreover, 2a,b coupled with aryl diazonium salt in the presence of sodium hydroxide to yield 3-(benzofuran-5-yl)-2-aryl-hydrazono-3-oxo-propanals 8a,b which were excellent precursors for the synthesis of pyridazines 9,12. © 2003 Wiley Periodicals, Inc. 15:85,91, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10219 [source] Developmental toxicity evaluation of inhaled tertiary amyl methyl ether in mice and ratsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2003Frank Welsch Abstract This evaluation was part of a much more comprehensive testing program to characterize the mammalian toxicity potential of the gasoline oxygenator additive tertiary amyl methyl ether (TAME), and was initiated upon a regulatory agency mandate. A developmental toxicity hazard identi,cation study was conducted by TAME vapor inhalation exposure in two pregnant rodent species. Timed-pregnant CD®(Sprague-Dawley) rats and CD-1® mice, 25 animals per group, inhaled TAME vapors containing 0, 250, 1500 or 3500 ppm for 6 h a day on gestational days 6,16 (mice) or 6,19 (rats). The developmental toxicity hazard potential was evaluated following the study design draft guidelines and end points proposed by the United States Environmental Protection Agency. Based on maternal body weight changes during pregnancy, the no-observable-adverse-effect level (NOAEL) was 250 ppm for maternal toxicity in rats and 1500 ppm for developmental toxicity in rats using the criterion of near-term fetal body weights. In mice, more profound developmental toxicity was present than in rats, at both 1500 and 3500 ppm. At the highest concentration, mouse litters revealed more late fetal deaths, signi,cantly reduced fetal body weights per litter and increased incidences of cleft palate (classi,ed as an external malformation), as well as enlarged lateral ventricles of the cerebrum (a visceral variation). At 1500 ppm, mouse fetuses also exhibited an increased incidence of cleft palate and the dam body weights were reduced. Therefore, the NOAEL for the mouse maternal and developmental toxicity was 250 ppm under the conditions of this study. Copyright © 2003 John Wiley & Sons, Ltd. [source] Two-generation reproductive toxicity study of inhaled tertiary amyl methyl ether (TAME) vapor in CD® ratsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2003R. W. Tyl Abstract Under Of,ce of Prevention, Pesticides and Toxic Substances draft guidelines, CD® weanling F0 rats (30 of each gender per group) inhaled tertiary amyl methyl ether vapor at 0, 250, 1500 or 3000 ppm 5 days a week and 6 h a day for 10 weeks, with vaginal cytology evaluated for weeks 8,10. The F0 animals then produced F1 offspring, with exposure 7 days a week from mating through to lactation. During the F1 prebreed exposure period, vaginal patency, preputial separation (PPS) and vaginal cytology were evaluated. The F1 animals were mated, with F2 anogenital distance measured on postnatal day zero. At F2 weaning 30 of each gender per group were selected for postwean retention, with no exposures, through vaginal patency and PPS. Body weights, feed consumption and clinical signs were recorded throughout the study. Adult F0 and F1 systemic toxicity was present at 1500 and 3000 ppm. Minor adult male reproductive toxicity was present at 3000 ppm. There were no adult effects on vaginal cyclicity, estrous cycle length, mating, fertility, pregnancy, gestational length or ovarian and uterine weights. There were no treatment-related gross or histopathologic ,ndings in parental male or female systemic or reproductive organs. The F1 and F2 offspring toxicity was present at 1500 and 3000 ppm. The no-observable-adverse-effect level for adult systemic and offspring toxicity was 250 ppm and 1500 ppm for male reproductive toxicity (females at >3000 ppm). Copyright © 2003 John Wiley & Sons, Ltd. [source] Collision-induced loss of AgH from Ag+ adducts of alkylamines, aminocarboxylic acids and alkyl benzyl ethers leads exclusively to thermodynamically favored product ionsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2009Mathias Schäfer Abstract The loss of AgH from [M + Ag]+ precursor ions of tertiary amines, aminocarboxylic acids and aryl alkyl ethers is examined by deuterium labeling combined with collision activation (CA) dissociation experiments. It was possible to demonstrate that the AgH loss process is highly selective toward the hydride abstraction. For tertiary amines and aminocarboxylic acids, hydrogen originates from the ,-methylene group carrying the nitrogen function (formation of an immonium ion). In all cases examined, the most stable, i.e. the thermodynamically favored product ion is formed. In the AgH loss process, a large isotope effect operates discriminating against the loss of D. The [M + Ag]+ ion of benzyl methyl ether loses a hydride ion exclusively from the benzylic methylene group supporting the experimental finding that the AgH loss reaction selectively cleaves the weakest CH bond available. Copyright © 2008 John Wiley & Sons, Ltd. [source] Quantitative analysis of the P-glycoprotein inhibitor Elacridar (GF120918) in human and dog plasma using liquid chromatography with tandem mass spectrometric detectionJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 10 2004Ellen Stokvis Abstract A liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method for the determination of the P-glycoprotein and breast cancer resistance protein inhibitor Elacridar in human and dog plasma is described. The internal standard was stable isotopically labelled Elacridar. Sample pretreatment involved liquid,liquid extraction with tert -butyl methyl ether. Analysis of Elacridar and internal standard was performed by reversed-phase LC on a basic stable minibore analytical column with an eluent consisting of acetonitrile and aqueous ammonia. An API-2000 triple-quadrupole mass spectrometer with an electrospray ion source was used in the positive-ion multiple reaction monitoring mode. The run time per sample was only 6 min. The method is sensitive and specific, with a dynamic range from 1 to 500 ng ml,1 from 100 µl of human or dog plasma. The accuracy of the method was within 15% bias and the precision was lower than 15% for all tested concentration levels and in both matrices. The method is simple and the liquid,liquid extraction produces clean samples. This method was successfully applied to support the pharmacokinetics of a clinical trial in which orally applied Elacridar was used as a bioavailability enhancer. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||