title: Rapid resolution liquid chromatography-mass spectrometry and high-performance liquid chromatography-fluorescence detection for metabolism and pharmacokinetic studies of ergosta-4,6,8(14),22-tetraen-3-one.
abstract: Ergosta-4,6,8(14),22-tetraen-3-one (ergone) from many medicinal plants has been demonstrated to possess a variety of pharmacological activities in vivo and in vitro, including cytotoxic, diuretic and immunosuppressive activity. Metabolism and pharmacokinetic studies on rat were conducted for ergone. Rapid resolution liquid chromatography with atmospheric pressure chemical ionization tandem multi-stage mass spectrometry (RRLC-APCI-MS(n)) and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) methods were applied for the identification and quantification of ergone and its metabolite from rat plasma, faeces and urine. A metabolite was identified by RRLC-DAD-APCI-MS(n): 22,23-epoxy-ergosta-4,6,8(14)-triaen-3-one (epoxyergone). The concentrations of the analyte with its metabolites were determined by HPLC-FLD at excitation wavelength of 370 nm and emission wavelength of 485 nm. The samples were deproteinized with methanol after addition of camptothecin as internal standard (IS). The analysis was performed on a Diamonsil C18 column (150 mm x 4.6 mm x 5 microm) with a mobile phase gradient consisting of methanol and water at a flow rate of 1 mL min(-1). The assay was linear over the concentration range of 42-1500, 36-7500 and 42-1500 ng mL(-1) for plasma, faecal homogenate and urine respectively. The absolute recoveries were found to be 97.0+/-1.2%, 98.1+/-0.7% and 96.6+/-1.8% for plasma, faecal homogenate and urine respectively. The intra-day and inter-day relative standard deviations (RSD) were less than 10%. The previous HPLC-MS/MS method is not affordable for most laboratories because of the specialty requirement and high equipment cost. However, the HPLC-FLD method is economic and operating simply for quantitative determination of ergone and its metabolite in rat plasma, faeces and urine. In addition, liquid chromatography coupled with ion trap multi-stage mass spectrometry is becoming a useful technique for ergone metabolite identification.
authors.affiliation: Biomedicine Key Laboratory of Shaanxi Province, The College of Life Sciences, Northwest University, No. 229 Taibai North Road, Xi'an, Shaanxi 710069, China.
authors.forename: Ying-Yong
authors.initials: YY
authors.lastname: Zhao
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Qin
authors.forename: Xian-Long
authors.initials: XL
authors.lastname: Cheng
authors.forename: Xue-Ying
authors.initials: XY
authors.lastname: Liu
authors.forename: Rui-Chao
authors.initials: RC
authors.lastname: Lin
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiao-Ye
authors.initials: XY
authors.lastname: Li
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Sun
authors.forename: Wen-Ji
authors.initials: WJ
authors.lastname: Sun
mesh_terms: D000818:Animals; D002783:Cholestenones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods*; D003603:Cytotoxins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000493:pharmacokinetics*; D005453:Fluorescence; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000493:pharmacokinetics*; D016014:Linear Models; D013058:Mass Spectrometry / Q000191:economics / Q000379:methods*; D055492:Polyporus / Q000737:chemistry*; D051381:Rats; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D002783:Cholestenones; D003603:Cytotoxins; D007166:Immunosuppressive Agents; C015860:ergosta-4,6,8(14),22-tetraen-3-one