In this study, a simple and rapid ultra-fast liquid chromatography tandem mass spectrometry method was established and validated to determine ginsenosides Rb2 in rat plasma. Acetonitrile-mediated protein precipitant was applied to the sample preparation. Chromatographic separation was carried out on an Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 μm). The analytes were monitored using multiple reactions monitoring mode with precursor-to-product ion transitions at m/z 1077.4–945.3 and m/z 799.8 → 637.8 for ginsenoside Rb2 and internal standard, respectively. The mobile phase was composed of 0.1% formic acid aqueous solution and acetonitrile. The assay showed excellent linearity over the concentration range of 2–1,000 ng/ml, with correlation coefficient >0.995. The method was further validated for selectivity, precision, accuracy, recovery, and stability according to the US Food and Drug Administration guidelines. The validated method was successfully applied to pharmacokinetic and bioavailability studies of ginsenoside Rb2 in rat plasma. Based on the pharmacokinetic results, ginsenoside Rb2 showed slow clearance and low oral bioavailability (0.15%). In addition, the metabolites of ginsenoside Rb2 in rat urine and feces were characterized according to their accurate masses and fragment ions. The proposed metabolic pathway was deglycosylation.

中文翻译：

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液相色谱-电喷雾电离串联质谱法研究人参皂苷Rb2在大鼠体内的药代动力学和代谢

本研究建立并验证了一种简单快速的超快速液相色谱串联质谱法，用于测定大鼠血浆中的人参皂苷 Rb2。将乙腈介导的蛋白质沉淀剂应用于样品制备。在 Acquity UPLC HSS T3 柱（100 × 2.1 mm，1.8 μm）上进行色谱分离。使用多反应监测模式监测分析物，在m/z 1077.4–945.3 和m/z处进行母离子到产物离子的跃迁人参皂苷 Rb2 和内标分别为 799.8 → 637.8。流动相由0.1%甲酸水溶液和乙腈组成。该测定在 2–1,000 ng/ml 的浓度范围内显示出极好的线性，相关系数 >0.995。根据美国食品和药物管理局的指导方针，进一步验证了该方法的选择性、精密度、准确度、回收率和稳定性。经验证的方法已成功应用于大鼠血浆中人参皂苷 Rb2 的药代动力学和生物利用度研究。根据药代动力学结果，人参皂苷 Rb2 显示出缓慢清除和低口服生物利用度 (0.15%)。此外，还根据准确质量和碎片离子对大鼠尿液和粪便中人参皂苷 Rb2 的代谢物进行了表征。