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是一种新型恶唑烷酮抗结核药，在体外和体内对结核分枝杆菌，特别是耐多药结核病（MDR-TB）具有有效的抗菌活性。在这项研究中，在确定母体药物OTB-658的代谢物后，建立了一种特异性灵敏的液相色谱-串联质谱（LC-MS / MS）方法，并验证了该方法可定量OTB-658及其代谢物OTB-665和OTB-猴血698。HTB-1658的类似物HHY-1442被用作内标。通过直接蛋白质沉淀制备血液样品。在Zorbax SB C18色谱柱（50 mm×2.1 mm，3.5μm）上进行分离，使用甲醇/水的梯度流动相，流速为0.3 mL / min。通过在三重四极杆MS上以多重反应监测模式进行正电喷雾电离进行检测。所监测的转变为米/ ž 382.2→221.1为OTB-658，米/ž 398.2→308.1为OTB-665，米/ ž 414.1→372.3为OTB-698和米/ ž分别418.2→311.3为HHY-1442，。对于OTB-658和OTB-665，在10-2000 ng / mL的范围内，对于OTB-698，在5-1000 ng / mL的范围内，观察到良好的线性。三种分析物的日内和日间精度均低于8.4％，精度范围为96.0％至106.0％。在储存，制备和分析过程中，所有分析物均稳定。经验证的方法已成功应用于OTB-658在食蟹猴中的药代动力学和生物利用度研究，口服剂量10 mg / kg时，OTB-658的绝对生物利用度为25.0％。