LC-MS/MS快速测定不同采摘时间银杏叶中银杏内酯和白果内酯的含量

Determination of Ginkgolides and Bilobalide in Ginkgo biloba L.Leaves Collected in Various Months by LC-MS/MS

目的建立银杏叶中银杏内酯和白果内酯的高效液相电喷雾二级质谱(LC-MS/MS)定量分析方法,并对不同采摘时间银杏叶中银杏内酯和白果内酯含量进行测定。方法银杏叶样品以甲醇-水(1:9)提取,并用乙酸乙酯萃取,采用Phenomenex ODS柱分离,流动相为甲醇-水(60:40),流速0.7 mL·min^(-1)。电离方式为电喷雾正离子,采用多反应检测模式(MRM),捡测离子分别为m/z 409.4→345.3(银杏内酯A)、m/z 425.3→361.3(银杏内酯B)、m/z 441.4→325.3(银杏内酯C)和m/z 327.4→309.3(白果内酯)。结果分析过程仅需8.5 min,且无杂质干扰,4种成分回收率为91.79%～101.48%银杏内酯A,B和白果内酯含量分别在7月18日、8月19日和7月5日采摘的样品达到最高。结论方法快速、准确、选择性好,适合银杏内酯和白果内酯的定量分析,七月份叶子中内酯含量最高,为最佳采摘时间。

OBJECTIVE To establish a LC/MS/MS method for the determination of ginkgolides and bilobalide in Ginkgo biloba L. leaves collected in various months, and varify the optimum time to harvest leaves. METHODS Samples were extracted with methanol-water （1： 9） , partitioned with ethyl acetate, and analyzed by HPLC coupled with electrospray tandem mass spectrometry in positive ion mode. Chromatographic separation was performed on a C18 column eluted with methanol-water （60： 40） at 0. 7 mL·min^-1 The most abundant precursor/product ion pairs [ m/z 409. 4→345.3 for ginkgolide A （ GA）, m/z 425.3→361.3 for ginkgolide B （GB）, m/z 441.4→325.3 for ginkgolide C （GC） , and m/z 327.4→309. 3 for bilobalide （BB） ] were selected in multiple reaction monitoring （MRM） mode. RESULTS The total analytical time was 8.5 min. The recoveries of the analytes ranged from 91.79% to 101.48%. The maximum contents of GA, GB, and BB were found in the samples collected on July 18th, August 19th and July 5th, respectively. CONCLUSION The method was rapid, selective, accurate and suitable for the quantitative analysis of ginkgolides and bilobalide. July was suggested as the optimum time to harvest the leaves.