ABSTRACT
<p><b>AIM</b>To establish a rapid and sensitive LC-MSn method for the identification of trigonelline and its main metabolites in rat urine.</p><p><b>METHODS</b>After optimizing the detection conditions of LC-MSn chromatography and mass spectrometry using trigonelline, its ionization and cleavage in ESI-MS and ESI-MSn modes were summarized, then serving as the basis for the metabolite analysis of trigonelline in rat urine. The 0-48 h urine samples of rats were collected after iv 8 mg x kg(-1) trigonelline, then, the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC-MSn.</p><p><b>RESULTS</b>The structures of trigonelline metabolites were elucidated according to the changes of the molecular weights of the metabolites (deltaM) and their cleavage pattern in ESI-ITMSn. As a result, two phase I metabolites and the parent drug were identified existing in rat urine, and two phase II metabolites were identified.</p><p><b>CONCLUSION</b>The LC-MSn method is rapid and high sensitive and specific, it is suitable for the identification of trigonelline and its metabolites in rat urine.</p>
Subject(s)
Animals , Male , Rats , Alkaloids , Chemistry , Metabolism , Chromatography, High Pressure Liquid , Methods , Hypoglycemic Agents , Chemistry , Metabolism , Plants, Medicinal , Chemistry , Rats, Wistar , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization , Methods , Trigonella , ChemistryABSTRACT
<p><b>AIM</b>To identify the main metabolites of stachydrine in rat.</p><p><b>METHODS</b>The ionization, cleavage and chromatographic characteristics of stachydrine were studied by using high-performance liquid chromatography-electrospray ionization ion trap tandem mass spectrometry (HPLC-ESI/MS) for the first time. These characteristics of stachydrine were used as the basis for the analyses of metabolites in rat urine. The 0 - 24 h urine samples of rats after ig 25 mg x kg(-1) stachydrine were collected and purified by using C10 solid-phase extraction cartridge, and then analyzed by HPLC-ESI/MS to identify stachydrine and its metabolites.</p><p><b>RESULTS</b>The parent drug (stachydrine), 6 phase I metabolites (N-demethyl, dehydrogenation, ring-oxidation) and 2 phase II metabolites (glycine conjugates of 2 ring-oxidation products) were identified existing in rat urine.</p><p><b>CONCLUSION</b>The presented method was proved to be sensitive, rapid, high selective and specific for the identification of stachydrine and its metabolites in rat urine.</p>
Subject(s)
Animals , Rats , Chromatography, High Pressure Liquid , Methods , Plant Roots , Chemistry , Plants, Medicinal , Chemistry , Proline , Metabolism , Urine , Rats, Wistar , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization , Methods , Stachys , ChemistryABSTRACT
<p><b>AIM</b>To estabilish a rapid and sensitive LC-ESI-ITMSn method for the identification of ephedrine and its main metabolites in rat urine.</p><p><b>METHODS</b>After optimizing the detection condition of LC-ESI-ITMSn chromatography and mass spectrometry by using a standard ephedrine, the ionization and cleavage rules of ephedrine in ESI-MS and ESI-MSn modes were summarized, and then serving as the basis for the metabolite analysis of ephedrine in rat urine. Rat urine samples of 0-48 h were collected after ig 10 mg x kg(-1) ephedrine, then the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC-ESI-ITMSn.</p><p><b>RESULTS</b>The structures of ephedrine metabolites were elucidated according to the changes of the molecular weights of the metabolites (deltaM) and their cleavage pattern in ESI-ITMSn. As a result, three phase I metabolites and the parent drug ephedrine were identified existing in rat urine, but no phase II metabolites were found.</p><p><b>CONCLUSION</b>The LC-ESI-ITMSn method is rapid and highly sensitive and sepecific, it is suitable for the identification of ephedrine and its metabolites in rat urine.</p>
Subject(s)
Animals , Male , Rats , Chromatography, High Pressure Liquid , Methods , Ephedrine , Chemistry , Metabolism , Urine , Molecular Weight , Rats, Wistar , Sensitivity and Specificity , Spectrometry, Mass, Electrospray Ionization , MethodsABSTRACT
Objective To provide reliable and scientific data for supervision assessment and control of regional ambient air quality in Beijing through the investigation of ambient air quality in Chaoyang District. Methods Three local regions of Chaoyang Park Dabeiyao and Dongzhimen were selected as the measurement areas the determinations of air quality of consecutive 5 days and 4 times a day8 00 12 00 16 00 20 00 were conducted 6 items were included PM10 CO NO2 SO2 and negative ion concentration. Results The daily averages of CO and SO2 were lower than level 2 standard limitation for 5 days’ measurement in 3 regions. 2 of 5 days the daily average of NO2 in Dongzhimen exceeded the standard limitation0.01 mg/m3. 2 of 5 days the daily average of PM10 in 3 regions exceeded the standard limitation 0.01- 0.04 mg/m3. Conclusion Preliminary analysis was carried out based on ambient air quality data in 3 local regions the air pollution often emerged on some days in Beijing. The supervision and control should be conducted according to the characters of regional environmental quality pollution and meteorology.