Department of Pharmacy, Kunming General Hospital of Chengdu Military Region, Kunming, PR China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2011 Jun 1;879(19):1653-8. doi: 10.1016/j.jchromb.2011.04.003. Epub 2011 Apr 12.
A new LC-ESI-MS/MS assay method has been developed and validated for the quantification of swertiamarin, a representative bioactive substance of Swertia plants, in rat plasma using gentiopicroside, an analog of swertiamarin on chemical structure and chromatographic action, as the internal standard (IS). The swertiamarin and IS were extracted from rat plasma using solid-phase extraction (SPE) as the sample clean-up procedure, and they were chromatographed on a narrow internal diameter column (Agilent ZORBAX ECLIPSE XDB-C(18) 100 mm × 2.1 mm, 1.8 μm) with the mobile phase consisting of methanol and water containing 0.1% acetic acid (25:75, v/v) at a flow rate of 0.2 mL/min. The detection was performed on an Agilent G6410B tandem mass spectrometer by negative ion electrospray ionisation in multiple-reaction monitoring mode while monitoring the transitions of m/z 433 M+CH(3)COO→179 and m/z 415 M+CH(3)COO→179 for swertiamarin and IS, respectively. The lower limit of quantification (LLOQ) was 5 ng/mL within a linear range of 5-1000 ng/mL (n=7, r(2)≥0.994), and the limit of detection (LOD) was demonstrated as 1.25 ng/mL (S/N≥3). The method also afforded satisfactory results in terms of sensitivity, specificity, precision (intra- and inter-day), accuracy, recovery, freeze/thaw, long-time stability and dilution integrity. This method was successfully applied to determination of the pharmacokinetic properties of swertiamarin in rats after oral administration at a dose of 20 mg/kg. The following pharmacokinetic parameters were obtained (mean): maximum plasma concentration, 1920.1 ng/mL; time to reach maximum plasma concentration, 0.945 h; elimination half-time, 1.10h; apparent total clearance, 5.638 L/h/kg; and apparent volume of distribution, 9.637 L/kg.
建立了一种新的 LC-ESI-MS/MS 测定方法，用于定量大鼠血浆中的獐牙菜苦苷，一种獐牙菜属植物的代表性生物活性物质，以龙胆苦苷（獐牙菜苦苷在化学结构和色谱行为上的类似物）为内标（IS）。采用固相萃取（SPE）作为样品净化程序，从大鼠血浆中提取獐牙菜苦苷和 IS，采用甲醇和含 0.1%乙酸的水（25:75，v/v）作为流动相，在内径为 100mm×2.1mm、1.8μm 的窄内径柱（Agilent ZORBAX ECLIPSE XDB-C(18)）上进行色谱分离，流速为 0.2mL/min。采用 Agilent G6410B 串联质谱仪，在负离子电喷雾电离模式下，以多反应监测模式进行检测，同时监测 m/z 433 M+CH(3)COO→179 和 m/z 415 M+CH(3)COO→179 的跃迁，分别为獐牙菜苦苷和 IS。定量下限（LLOQ）为 5ng/mL，线性范围为 5-1000ng/mL（n=7，r(2)≥0.994），检测限（LOD）为 1.25ng/mL（S/N≥3）。该方法在灵敏度、特异性、精密度（日内和日间）、准确度、回收率、冻融、长期稳定性和稀释完整性方面也取得了令人满意的结果。该方法成功应用于 20mg/kg 剂量口服给药后大鼠獐牙菜苦苷的药代动力学研究。获得以下药代动力学参数（平均值）：最大血浆浓度，1920.1ng/mL；达峰时间，0.945h；消除半衰期，1.10h；表观总清除率，5.638L/h/kg；表观分布容积，9.637L/kg。
