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| 基于多级质谱裂解规律结合SD大鼠在体肠襻给药模型研究西地那非经肠吸收与代谢特性 |
| 礼嵩1,2,3△,倪海涛4△,盛夏1,唐守艳1,陆雯静1,程春燕1,李伟3,范国荣2*,孙颖浩1* |
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(1. 第二军医大学长海医院泌尿外科GCP平台, 上海 200433;
2. 第二军医大学药学院药物分析学教研室, 上海市药物(中药)代谢产物研究重点实验室, 上海 200433;
3. 沈阳药科大学药学院药物分析学教研室, 沈阳 110016;
4. 第二军医大学基础部组织学与胚胎学教研室, 上海 200433
△共同第一作者
*通信作者) |
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| 摘要: |
| 目的 探讨西地那非及其活性代谢产物N-去甲西地那非的液相色谱-电喷雾多级质谱[LC-ESI（+）MSn]裂解规律，考察西地那非经肠吸收与代谢特征。 方法 采用ESI质谱分析技术，在正离子检测模式下，分别对西地那非、N-去甲西地那非进行LC-ESI（+）MSn裂解分析，解析其中的主要碎片离子以及可能的裂解途径。基于裂解规律建立西地那非、N-去甲西地那非的LC-ESI（+）MS/MS的SD大鼠血浆样品分析方法，取25只成年健康雄性SD大鼠，随机分成5组，每组5只，以在体肠襻给药模型法给予硫酸氢钠西地那非原料药10 mg/kg，于给药前及给药后0.25、0.5、1、4 h时在肝门静脉处取血测定，每个时间点一组SD大鼠，考察药物经肠道吸收及在肠系膜处代谢情况。 结果 质谱裂解规律表明，西地那非及N-去甲西地那非均获得丰度较高的m/z 311、283特征碎片质谱峰，证明药物在C-S键处不稳定易发生断裂脱去C5H12O2N2S，在乙氧基C-O键处不稳定易发生断裂脱去C2H4，最终形成稳定m/z 283碎片离子。以m/z 475→m/z 283（西地那非）和m/z 461→m/z 283（N-去甲西地那非）为离子反应监测通道对在体肠襻给药模型进行半定量分析，结果表明除以原型药物西地那非的形式吸收外，在体肠中约有1/5原型药物经肠代谢生成活性代谢产物N-去甲西地那非，并与原型药物同时吸收。 结论 西地那非和N-去甲西地那非经质谱裂解均形成稳定的m/z 283二级碎片离子；西地那非在体肠吸收时伴随氮去甲基代谢反应同时发生，约有1/5的原型药物代谢生成活性代谢产物N-去甲西地那非。 |
| 关键词: 西地那非 N-去甲西地那非 在体肠襻给药模型 质谱裂解 |
| DOI：10.3724/SP.J.1008.2014.00061 |
| 投稿时间：2013-06-17修订日期：2013-08-02 |
| 基金项目:国家“重大新药创新”科技专项（2012ZX09303-011-002，2009ZX09301-011-07）。 |
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| Intestinal absorption and metabolic characteristics of sildenafil: a study using in situ intestinal administration rat model based on mass fragmentation pathway |
| LI Song1,2,3△, NI Hai-tao4△, SHENG Xia1, TANG Shou-yan1, LU Wen-jing1, CHENG Chun-yan1, LI Wei3, FAN Guo-rong2*, SUN Ying-hao1* |
(1. GCP Office, Department of Urology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China;
2. Department of Pharmaceutical Analysis, School of Pharmacy, Second Military Medical University & Key Laboratory of Shanghai Drug (Chinese Materia Medica) Metabolism Research, Shanghai 200433, China;
3. Department of Pharmaceutical Analysis, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, Liaoning, China;
4. Department of Histology and Embryology, College of Basic Medical Sciences, Second Military Medical University, Shanghai 200433, China
△Co-first authors.
*Corresponding author.) |
| Abstract: |
| Objective To investigate the fragmentation pathways of sildenafil and its active metabolite N-desmethylsildenafil, so as to understand the intestinal absorption and metabolic characteristics of sildenafil. Methods Using electrospray ion technology (positive ion mode), we analyzed the fragmentation pathways of sildenafil and its active metabolite N-desmethylsildenafil. Based on the rule of cracking, a LC-ESI(+)MS/MS method was developed to determine the intestinal absorption of sildenafil and metabolism of active metabolites N-desmethylsildenafil in the mesenterium. Totally 25 healthy adult male SD rats were randomly divided into five groups and each group contained 5 rats. The hepatic portal venous blood samples were obtained from rats after intestinal administration of 10 mg/kg of sildenafil citrate. The absorption and metabolism were examined in the in situ intestinal administration model at premedication, 0.25 h, 0.5 h, 1 h and 4 h (five groups) after medication. Results Mass spectrometric pyrolysis of sildenafil and its active metabolite N-demethylsildenafil showed ion peaks m/z 311 and 283, indicating that the C-S bond was unstable and was liable to lose C5H12O2N2S, and the C-O bond was unstable and was liable to lose C2H4, finally forming stable fragment ions. When m/z 475→m/z 283 (sildenafil) and m/z 461→m/z 283 (N-demethylsildenafil) were used as ion reaction channel, sildenafil were absorbed not only in the form of sildenafil in the intestine, but also in the form of its active metabolite N-demethylsildenafil metabolisming as 1/5 of the prototype drugs were finally changed into N-demethylsildenafil. Conclusion Both sildenafil and N-demethylsildenafil can be cracked into stable m/z 283 secondary ions. Intestinal absorption is accompanied by its nitrogen demethylation reaction, which leads to the fact that about 1/5 of prototype drug metabolized into active metabolite N-demethylsildenafil. |
| Key words: sildenafil N-desmethylsildenafil in situ intestinal administration model mass fragmentation |
