Sinomenine is an active ingredient extracted from herb medicine, which has been prescribed to treat rheumatoid arthritis in clinics. The present work was to develop a simple method to simultaneously determine sinomenine and its metabolites desmethyl sinomenine and sinomenine N-oxide in rat plasma by liquid chromatography tandem mass spectrometry. Precursor-to-product transitions for detection were m/z 330.2 > 239.1 for sinomenine, m/z 316.2 > 239.1 for desmethyl-sinomenine, m/z 346.2 > 314.1 for sinomenine N-oxide and m/z 286.2 > 153.2 for morphine (internal standard), respectively. During the validation and sample quantification, an excellent linear calibration range was observed for all the analytes with correlation coefficients more than 0.999 (r > 0.99). The extraction recovery was more than 85%. No significant matrix effect and carryover were observed. The precision was less than 6.45%, whereas accuracy ranged from –4.10% to 7.23%. The validated method has been successfully applied to the pharmacokinetic study of sinomenine, desmethyl sinomenine, and sinomenine N-oxide in rat plasma after oral administration of sinomenine at a single dose of 5 mg/kg. The results suggested that sinomenine was rapidly metabolized into its metabolite desmethyl sinomenine and sinomenine N-oxide.

中文翻译：

---

液相色谱-串联质谱法同时测定大鼠血浆中青藤碱及其代谢物去甲基青藤碱和青藤碱N-氧化物

青藤碱是从草药中提取的活性成分，临床上用于治疗类风湿性关节炎。本工作旨在建立一种液相色谱串联质谱法同时测定大鼠血浆中青藤碱及其代谢物去甲基青藤碱和青藤碱N-氧化物的简便方法。用于检测的前体到产物的转变为：青藤碱m / z 330.2 > 239.1，去甲基青藤碱 m/z 316.2 > 239.1，青藤碱N-氧化物m / z 346.2 > 314.1，吗啡m / z 286.2 > 153.2（内标），分别。在验证和样品定量过程中，所有分析物都观察到良好的线性校准范围，相关系数超过 0.999 ( r > 0.99)。提取回收率大于85%。没有观察到显着的基质效应和残留。精度低于 6.45%，准确度范围为 –4.10% 至 7.23%。该方法已成功应用于单剂量口服青藤碱5 mg/kg后大鼠血浆中青藤碱、去甲基青藤碱和青藤碱N-氧化物的药动学研究。结果表明，青藤碱快速代谢为其代谢物去甲基青藤碱和青藤碱N-氧化物。