Chen Huaixia, Chen Yong, Du Peng, Han Fengmei
Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China.
J Chromatogr Sci. 2008 Jan;46(1):74-80. doi: 10.1093/chromsci/46.1.74.
In vivo and in vitro metabolism of scopolamine is investigated using a highly specific and sensitive liquid chromatography-mass spectrometry (LC-MSn) method. Feces, urine, and plasma samples are collected individually after ingestion of 55 mg/kg scopolamine by healthy rats. Rat feces and urine samples are cleaned up by a liquid-liquid extraction and a solid-phase extraction procedure (C18 cartridges), respectively. Methanol is added to rat plasma samples to precipitate plasma proteins. Scopolamine is incubated with homogenized liver and intestinal flora of rats in vitro, respectively. The metabolites in the incubating solution are extracted with ethyl acetate. Then these pretreated samples are injected into a reversed-phase C18 column with mobile phase of methanol-ammonium acetate (2 mM, adjusted to pH 3.5 with formic acid) (70:30, v/v) and detected by an on-line MSn system. Identification and structural elucidation of the metabolites are performed by comparing their changes in molecular masses (DeltaM), retention-times and full scan MSn spectra with those of the parent drug. The results reveal that at least 8 metabolites (norscopine, scopine, tropic acid, aponorscopolamine, aposcopolamine, norscopolamine, hydroxyscopolamine, and hydroxyscopolamine N-oxide) and the parent drug exist in feces after administering 55 mg/kg scopolamine to healthy rats. Three new metabolites (tetrahydroxyscopolamine, trihydroxy-methoxyscopolamine, and dihydroxy-dimethoxyscopolamine) are identified in rat urine. Seven metabolites (norscopine, scopine, tropic acid, aponorscopolamine, aposcopolamine, norscopolamine, and hydroxyscopolamine) and the parent drug are detected in rat plasma. Only 1 hydrolyzed metabolite (scopine) is found in the rat intestinal flora incubation mixture, and 2 metabolites (aposcopolamine and norscopolamine) are identified in the homogenized liver incubation mixture.
采用高特异性和高灵敏度的液相色谱-质谱联用（LC-MSn）方法，对东莨菪碱的体内外代谢情况进行了研究。健康大鼠摄入55mg/kg东莨菪碱后，分别收集粪便、尿液和血浆样本。大鼠粪便和尿液样本分别通过液-液萃取和固相萃取程序（C18柱）进行净化处理。向大鼠血浆样本中加入甲醇以沉淀血浆蛋白。东莨菪碱分别与大鼠的肝匀浆和肠道菌群在体外进行孵育。孵育液中的代谢产物用乙酸乙酯萃取。然后将这些预处理后的样本注入反相C18柱，流动相为甲醇-乙酸铵（2mM，用甲酸调至pH 3.5）（70:30，v/v），并通过在线MSn系统进行检测。通过比较代谢产物与母体药物的分子量变化（ΔM）、保留时间和全扫描MSn谱图，对代谢产物进行鉴定和结构解析。结果显示，给健康大鼠施用55mg/kg东莨菪碱后，粪便中至少存在8种代谢产物（去甲东莨菪碱、东莨菪醇、托品酸、阿扑去甲东莨菪碱、阿扑东莨菪碱、去甲东莨菪碱、羟基东莨菪碱和羟基东莨菪碱N-氧化物）以及母体药物。在大鼠尿液中鉴定出3种新的代谢产物（四羟基东莨菪碱、三羟基甲氧基东莨菪碱和二羟基二甲氧基东莨菪碱）。在大鼠血浆中检测到7种代谢产物（去甲东莨菪碱、东莨菪醇、托品酸、阿扑去甲东莨菪碱、阿扑东莨菪碱、去甲东莨菪碱和羟基东莨菪碱）以及母体药物。在大鼠肠道菌群孵育混合物中仅发现1种水解代谢产物（东莨菪醇），在肝匀浆孵育混合物中鉴定出2种代谢产物（阿扑东莨菪碱和去甲东莨菪碱）。
