液相色谱-质谱联用技术在药物代谢产物鉴定中的应用

药物代谢研究贯穿药物开发的整个过程。生物基质中药物代谢产物的快速、准确鉴定有助于理解药物或候选化合物的生物转化途径，确定代谢软位点，从而帮助优化先导物结构，筛选出具有更高代谢稳定性的药物。利用亲核性捕获试剂开展体外代谢实验，检测反应性代谢产物的生成，相关结果可以帮助规避候选化合物进入临床后可能产生的毒性风险。由于液相色谱-质谱联用技术（LC/MS）具有分析通量高、检测灵敏度高、选择性好、能提供丰富的结构相关信息等优点，其在药物代谢研究中的作用越来越重要。本工作综述了近年来作者所在实验室采用LC/MS法开展的药物代谢产物鉴定研究，提出了基于LC/MS技术的药物代谢产物鉴定研究的基本流程和药物在人体内的主要代谢产物，可为临床药动学研究和药物相互作用研究提供数据基础。

Applications of Liquid Chromatography-Mass Spectrometry in Drug Metabolite Identification

Drug metabolism study is an integral part of drug discovery and development. Quick and accurate identification of the metabolites that formed in the biological matrix is crucial for the understanding of biotransformation pathways of drugs or drug candidates. Information on the metabolic soft sites of a candidate could help the optimization of the lead compound to screen drugs that have higher metabolic stability. On the other hand, the use of nucleophilic capture reagents to carry out in vitro metabolism studies to screen reactive metabolites could avoid the possible toxicity risks in clinical practice. Because of its high speed, high sensitivity, good selectivity, and the ability to provide rich structure-related informations, liquid chromatography-mass spectrometry (LC/MS) has become a dominant tool in drug metabolism studies. In recent ten years, metabolism studies on more than one hundred drugs, drug candidates, or natural active compounds have been carried out in our lab by either liquid chromatography/ion trap mass spectrometry (LC/MSⁿ) or ultrahigh performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). At present, some drugs have either entered into clinical research or been approved for the treatment of multiple diseases by China Food and Drug Administration. This paper reviews the use of LC/MS in the drug metabolite identification studies in our lab, and offers thoughts on the general workflow for drug metabolite detection and structure elucidation using LC/MS. The workflow proposed in this review has focused on the metabolite identification studies on small-molecule xenobiotics. In addition, this review also discusses the advantages and disadvantages as well as the remaining challenges in drug metabolism and disposition studies using LC/MS technology. Principles of biological samples selection and preparation in drug metabolism studies has also been involved. In conclusion, the general workflow for small-molecule drug metabolism study using LC/MS has been proposed, which intends to provide a basis for clinical pharmacokinetics and drug-drug interaction studies.