Li Kai, Ding Li, Yang Zhong-Lin, Liu E-Hu, Qi Lian-Wen, Li Ping, Hu Yu-Zhu
China Pharmaceutical University, Ministry of Education, Nanjing, China.
Biomed Chromatogr. 2010 May;24(5):550-5. doi: 10.1002/bmc.1325.
Asperosaponin VI (also named akebia saponin D) is a typical bioactive triterpenoid saponin isolated from the rhizome of Dipsacus asper Wall (Dipsacaceae). In this work, a sensitive high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) assay has been established for determination of asperosaponin VI in rat plasma. With losartan as the internal standard (IS), plasma samples were prepared by protein precipitation with methanol. Chromatographic separation was performed on a C(18) column with a mobile phase of 10 mm ammonium acetate buffer containing 0.05% formic acid-methanol (32 : 68, v/v). The analysis was performed on an ESI in the selected ion monitoring mode using target ions at m/z 951.4 for asperosaponin VI and m/z 423.2 for the IS. The calibration curve was linear over the range 3-1000 ng/mL and the lower limit of quantification was 3.0 ng/mL. The intra- and inter-assay variability values were less than 9.5 and 7.8%, respectively. The accuracies determined at the concentrations of 3.0, 100.0, 300.0 and 1000 ng/mL for asperosaponin VI were within +/-15.0%. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of asperosaponin VI.
地奥司明（又名木通皂苷D）是从糙叶败酱（败酱科）根茎中分离得到的一种典型的具有生物活性的三萜皂苷。在本研究中，建立了一种灵敏的高效液相色谱 - 电喷雾电离 - 质谱（HPLC - ESI - MS）分析法，用于测定大鼠血浆中的地奥司明。以氯沙坦作为内标（IS），血浆样品采用甲醇蛋白沉淀法进行制备。色谱分离在C(18)柱上进行，流动相为含0.05%甲酸的10 mM醋酸铵缓冲液 - 甲醇（32 : 68，v/v）。在电喷雾电离源的选择离子监测模式下进行分析，地奥司明的目标离子为m/z 951.4，内标的目标离子为m/z 423.2。校准曲线在3 - 1000 ng/mL范围内呈线性，定量下限为3.0 ng/mL。批内和批间变异系数分别小于9.5%和7.8%。地奥司明在3.0、100.0、300.0和1000 ng/mL浓度下测定的准确度在±15.0%以内。所建立的验证方法成功应用于大鼠口服地奥司明后的药代动力学研究。
