高效液相色谱-电喷雾串联质谱法对氧化条件下缬草素降解产物的结构及氧化动力学研究

Study on Characterization of Degradation Products of Valtrate in Oxidation Condition and Its Oxidation Kinetics by HPLC-ESI MS/MS

建立了评价缬草素在氧化条件下稳定性的系统方法。采用高效液相色谱-电喷雾串联质谱(HPLC-ESI MS/MS)法对缬草素在氧化条件下(H2O2)的降解产物进行分离,并对主要降解产物进行结构鉴定,样品经Agilent Extend-C18分离,以乙腈-0.25%乙酸水溶液为流动相,梯度洗脱,质谱条件为电喷雾离子源(ESI),正离子模式检测。在上述条件下,共鉴定出4个主要降解产物,其中1个由标准品对照而得,4个化合物的结构母核均为缬草醛类成分。利用HPLC测定缬草素在H2O2中不同时间点的含量变化,经计算缬草素在H2O2中的变化符合一级动力学方程,10%的原型产物发生降解的时间为0.5 h。实验从定性和定量两方面揭示了缬草素的降解机制和降解规律,可为缬草素或含有缬草素的中药制剂的进一步研究与应用提供依据。

A systematic method for the estimation of stability of vahrate was established. HPLC - electrospray tandem mass spectrometry（ HPLC -ESI MS/MS） was applied to separate the degradation products of vahrate and identify structures of the main degradation products. The samples were sepa- rated on an Agilent Extend- C18 by gradient elution using acetonitrile-0. 25% acetic acid as mobile phase and analyzed under positive ion mode. Four degradation products were identified with the parent nucleus structures of baldrinals - compounds, in which one of oxidation products was identified through the reference substance. An HPLC method was established for the determination of the content change of valtrate in H2O2 at different time points. The result indicated that the content change of vahrate in H2O2 fits the first order kinetic equation, and the degradation of 10% prototype product occurred in 0. 5 h. This paper revealed the degradation mechanism and degradation rule of vahrate from two aspects of both qualitative and quantitative analysis, and provided a theoretical basis for further research.