Xu Lei, Song Rui, Tian Ji-Xin, Tian Yuan, Liu Guo-Qiang, Zhang Zun-Jian
Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China.
Biomed Chromatogr. 2012 Jul;26(7):808-15. doi: 10.1002/bmc.1734. Epub 2011 Oct 12.
Saikosaponins (SSs) are a class of triterpene saponins with a wide spectrum of bioactivities. A sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of saikosaponin a, saikosaponin c, saikosaponin d and saikosaponin b₂ in rat plasma. Plasma samples were prepared by liquid-liquid extraction. The analytes and the internal standard (IS) digoxin were well separated on an octadecyl column using gradient elution and analyzed by monitoring the fragmentation transition pair of anionic adducts to deprotonated molecules in negative-mode electrospray. By neutral loss of HCOOH, the transition pairs of m/z 825 → 779 for SSa, SSd, SSb₂ and the IS, and m/z 971 → 925 for SSc were sensitive for MS/MS detection with the lower limits of quantification in the range of 0.20-0.40 ng/mL. Method validation experiments were performed, including selectivity, precision, accuracy, linearity, matrix effect, recovery and stability. The validated method was further applied to determine the pharmacokinetics parameters of SSa, c and d in rats following a single oral administration of the extract of chaihu (the dried roots of Bupleurum chinense DC).
柴胡皂苷（SSs）是一类具有广泛生物活性的三萜皂苷。建立了一种灵敏的液相色谱串联质谱（LC-MS/MS）方法，用于同时测定大鼠血浆中的柴胡皂苷a、柴胡皂苷c、柴胡皂苷d和柴胡皂苷b₂。血浆样品采用液-液萃取法制备。在十八烷基柱上通过梯度洗脱对分析物和内标（IS）地高辛进行了良好的分离，并通过监测负离子模式电喷雾中去质子化分子的阴离子加合物的碎片转化对进行分析。通过甲酸的中性丢失，SSa、SSd、SSb₂和内标的m/z 825→779以及SSc的m/z 971→925的转化对在MS/MS检测中很灵敏，定量下限在0.20-0.40 ng/mL范围内。进行了方法验证实验，包括选择性、精密度、准确度、线性、基质效应、回收率和稳定性。经验证的方法进一步应用于单次口服柴胡（柴胡干燥根）提取物后大鼠体内SSa、c和d的药代动力学参数测定。
