Department of Drug Metabolism, State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Beijing Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, 1 Xian Nong Tan Street, Beijing 100050, PR China.
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, 1 Xian Nong Tan Street, Beijing 100050, PR China; Chinese Academy of Medical Sciences Key Laboratory of Anti-DR TB Innovative Drug Research, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, 1 Xian Nong Tan Street, Beijing 100050, PR China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Mar 15;1167:122552. doi: 10.1016/j.jchromb.2021.122552. Epub 2021 Jan 18.
OTB-658, a novel oxazolidinone anti-tuberculosis agent, has potent antibacterial activity against Mycobacterium tuberculosis, especially multi-drug resistant tuberculosis (MDR-TB) in vitro and in vivo. In this study, after metabolite identification of parent drug OTB-658, a specific and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established and validated to quantify OTB-658 and its metabolites OTB-665 and OTB-698 in monkey blood. HHY-1442, an analogue compound of OTB-658, was used as the internal standard. Blood samples were prepared by direct protein precipitation. Separation was performed on a Zorbax SB C18 column (50 mm × 2.1 mm, 3.5 μm) with a gradient mobile phase of methanol/water at a flow rate of 0.3 mL/min. The detection was conducted by a positive electrospray ionization in multiple-reaction monitoring mode on a triple quadrupole MS. The monitored transitions were m/z 382.2 → 221.1 for OTB-658, m/z 398.2 → 308.1 for OTB-665, m/z 414.1 → 372.3 for OTB-698 and m/z 418.2 → 311.3 for HHY-1442, respectively. Good linearity was observed over the range of 10-2000 ng/mL for OTB-658 and OTB-665, and 5-1000 ng/mL for OTB-698. All the intra-day and inter-day precision for the three analytes was below 8.4%, and the accuracy ranged from 96.0% to 106.0%. All analytes were stable during storage, preparation, and analytical procedures. The validated method was successfully applied to pharmacokinetic and bioavailability studies of OTB-658 in cynomolgus monkeys and the absolute bioavailability of OTB-658 was 25.0% at an oral dose of 10 mg/kg.
OTB-658 是一种新型噁唑烷酮类抗结核药物，对结核分枝杆菌具有很强的抗菌活性，尤其是对体外和体内的耐多药结核分枝杆菌（MDR-TB）。在这项研究中，在鉴定出母体药物 OTB-658 的代谢物后，建立并验证了一种灵敏、特异的液相色谱-串联质谱（LC-MS/MS）法，用于定量检测猴血中的 OTB-658 及其代谢物 OTB-665 和 OTB-698。HHY-1442 是 OTB-658 的类似物化合物，用作内标。血液样品采用直接蛋白沉淀法制备。采用甲醇/水为流动相，在 Zorbax SB C18 柱（50mm×2.1mm，3.5μm）上进行梯度洗脱，流速为 0.3mL/min。采用正电喷雾电离，在三重四极杆质谱上进行多反应监测模式检测。监测的离子对分别为 m/z 382.2→221.1（OTB-658）、m/z 398.2→308.1（OTB-665）、m/z 414.1→372.3（OTB-698）和 m/z 418.2→311.3（HHY-1442）。OTB-658 和 OTB-665 的线性范围为 10-2000ng/mL，OTB-698 的线性范围为 5-1000ng/mL。三种分析物的日内和日间精密度均低于 8.4%，准确度在 96.0%至 106.0%之间。所有分析物在储存、制备和分析过程中均稳定。该方法已成功应用于 OTB-658 在食蟹猴体内的药代动力学和生物利用度研究，口服 10mg/kg 剂量时，OTB-658 的绝对生物利用度为 25.0%。
