Comparative pharmacokinetics studies of benzoylhypaconine,benzoylmesaconine, benzoylaconine and hypaconitine in rats by LC‐MS method after administration of Radix Aconiti Lateralis Praeparata extract and Dahuang Fuzi Decoction

A rapid and sensitive high‐performance liquid chromatography–mass spectrometric (HPLC‐MS) method was developed and validated for simultaneous determination of benzoylhypaconine (BHA), benzoylmesaconine (BMA), benzoylaconine (BAC) and hypaconitine (HA) in rat plasma for the first time. The analytes were separated on a Kromasil C₁₈ column with a total running time of 11 min. The validation data demonstrated a sound feasibility for the newly developed method and it was then applied to the pharmacokinetic study of these analytes in rats. Pharmacokinetic behaviors of BHA, BMA, BAC and HA in rats were studied after oral administration of Radix Aconiti Lateralis Praeparata extract (FZ) and Dahuang Fuzi Decoction (DFD). The main parameters for the two groups of subjects were compared, and significant differences between Radix Aconiti Lateralis Praeparata extract group and Dahuang Fuzi Decoction group in calculated parameters, such as the area under the plasma concentration–time from zero to the last quantifiable time‐point (AUC_0–t), the area under the plasma concentration–time curve from zero to infinity (AUC_0–∞), peak plasma concentration (C_max), half‐life of elimination (T_1/2), mean retention time (MRT_0–t), plasma clearance (CL), volume of distribution (V_d) and time to reach C_max (T_max), were found. After oral administration of DFD, the AUC_0–t, AUC_0–∞ and C_max of BHA, BMA, BAC and HA decreased remarkably (p < 0.05) compared with those of the FZ extract group. V_d and CL values of BHA, BMA, BAC and HA increased, two of which showed significant difference (p < 0.05). T_1/2 and MRT_0–t values of BHA, BMA and BAC in the DFD group were significantly delayed compared with those of FZ extract group. Only the T_max of HA, the toxic ingredient in FZ, delayed significantly in DFD group compared with the value of FZ group. All these pharmacokinetic parameters were statistically compared, and the rationality of the combination for DFD was clearly demonstrated. Copyright © 2013 John Wiley & Sons, Ltd.     

柱切换液相色谱法快速定量检测参附注射液中乌头碱类生物碱和人参皂苷

利用柱切换液相色谱,建立了参附注射液中苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱和乌头碱6种乌头碱类生物碱,以及Rg1、Re、Rf、Rb1、Rc、Ro、Rb2、Rb3、Rd 9种人参皂苷的分析方法。首先利用强阳离子交换的在线固相小柱选择性富集和净化样品中生物碱类成分,优化了色谱条件;并采用EC－C18柱作为人参皂苷的分析柱,通过优化实验条件,结合柱切换方式,去除了样品中辅料等大极性基质成分对色谱柱的污染,实现了生物碱分析和人参皂苷分析的自动切换。结果显示,样品中的生物碱和人参皂苷分离良好,线性相关系数（r2）均大于0.999,连续进样精密度的相对标准偏差（RSD） < 2.0%,重复性的RSD < 2.0%;其中6种生物碱的平均回收率为95.1%～98.6%,检出限为4.0～8.2 ng/mL;9种人参皂苷的平均回收率为91.7%～104%。所构建的基于柱切换液相色谱技术的在线固相萃取方法能够有效去除样品中的基质干扰,快速完成参附注射液中3种单酯型生物碱和9种人参皂苷的快速定量,同时也可对3种双酯型生物碱进行限量检测,可应用于药物的质量评价。     

Effect of pH on the Metabolism of Aconitine under Rat Intestinal Bacteria and Analysis of Metabolites Using HPLC/MS-MSn Technique

A semi‐quantitative method of mass spectrometry (MS) has been described for the analysis of metabolites of aconitine by rat intestinal bacteria at different pH. At pH 7.0, the rat intestinal bacteria exhibit optimal activity for the metabolism of aconitine. A high‐performance liquid chromatography‐electrospray ionization multiple‐stage mass spectrometry (HPLC/ESI‐MSⁿ) method has been applied to investigate the characteristic product ions of metabolites. Then, the logical fragmentation pathways of metabolites have been proposed. By comparing the retention time (t_R) of HPLC and the ESI‐MSⁿ data with the data of standard compounds and reports from literature, ten metabolites have been identified and a distinctive metabolite (15‐deoxyaconitine) has been deduced first time. The experimental results demonstrate that HPLC/ESI‐MSⁿ is a specific and useful method for the identification of metabolites of aconitine. Also, in the present paper, the HPLC‐MS method was introduced to determine the synthetical metabolite prior to the study of the toxicity by the method of Bliss.