目的 研究不同pH条件下毛蕊花糖苷的降解规律，鉴定降解产物并推测降解途径。方法 采用HPLC-UV法研究毛蕊花糖苷在不同pH下的降解规律；采用高效液相色谱-离子阱飞行时间串联质谱（HPLC-IT-TOF-MS）鉴定其降解产物结构。使用Agilent ZORBAX Eclipse XDB C₁₈色谱柱（150 mm×4.6 mm，5 μm）；流动相为0.5%醋酸水溶液（A）-甲醇（B），体积流量1 mL/min，柱温30℃，检测波长254 nm，进样量10 μL；质谱分析使用电喷雾离子源（ESI），在正离子模式下扫描，扫描范围均为m/z 100～800。通过比较毛蕊花糖苷在不同pH条件下色谱峰面积，分析其降解规律；并通过对照品比对、质谱数据等对降解产物进行鉴定。结果 在不同pH缓冲溶液中，毛蕊花糖苷及异毛蕊花糖苷降解速率随pH值的增加而加快，降解产物有水解产物、氧化产物及同分异构体异毛蕊花糖苷等。结论 分析了不同pH条件下毛蕊花糖苷的降解规律、降解产物和降解途径，研究结果可为含毛蕊花糖苷的中药的质量控制提供参考。

Objective The degradation rule of verbascoside under different pH conditions was studied, degradation products was identified, and degradation pathways was speculated. Methods HPLC-UV was used to study the degradation rule of verbascoside at different pH values; High performance liquid chromatography tandem ion trap time-of-flight mass spectrometry (HPLC-IT-TOF-MS) was used to identify structures of degradation products. An Agilent ZORBAX Eclipse XDB C₁₈ column (4.6×150 mm, 5 μm) was used. The mobile phase consists of 0.5% acetic acid aqueous solution (A)-methanol (B). The flow rate was 1 mL/min. The column temperature was 30℃. The detection wavelength was 254 nm, and the injection volume was 10 μL. Mass spectrometry were acquired on a mass spectrometer with an electrospray ion source (ESI), and scanned in positive ion mode, with a scanning range of m/z 100-800. The degradation behaviors were analyzed by comparing the chromatographic peak areas of verbascoside at different pH values. Structures of degradation products were identified by comparing with the reference-substances and the mass spectrometry. Results In different pH buffer solutions, the degradation rate of verbascoside and isoverbascoside accelerated as increase of the pH value. The degradation products included hydrolysis products, oxidation products and isomeric products, etc. Conclusion In this study, the degradation rule, degradation products, and degradation pathways of verbascoside at different pH conditions were analyzed. It may provide a reference for the quality control of traditional Chinese medicines containing verbascoside.

R284.1

国家"重大新药创制"科技重大专项(2017ZX09301005)